Best OBD2 Scanner for Buying a Used Car in 2026: What to Bring, What the Screens Show, and What No Scanner Can Prove

We make PulsCar, which sells a membership with an OBDLink MX+; this is a comparison by us, with sources and dates. PulsCar is one of six picks below, and FIXD is checked as well; all are held to the same rules, except that PulsCar's screens are read from its own code, which we can see and the others' we cannot.

The question this page answers is narrow on purpose: which OBD2 scanner should you bring when you look at a used car, and what can it not tell you? A scanner reads what the car's computer is willing to say at the moment you plug in. That is valuable, because clearing a check engine light takes a scan tool and a few seconds, and the car keeps clues of that clearing that the next sections explain. It is also a small slice of what decides whether a used car is a good buy. For the full walk-around, paperwork and test-drive procedure, read our used car inspection checklist; this page does not repeat it. For what a professional pre-purchase inspection costs, read the car inspection cost guide. For the wider scanner shelf, read our best OBD2 scanner page.

The picks in sixty seconds: six tools, three situations

Six tools, grouped by the situation a buyer is in. The price is the one printed on the maker's own store on 22 October 2026 (the sale price where a sale is running; regular prices are in the sections on each tool). The note says what decided the pick for a used-car check specifically: whether the pages we saved print the screens a buyer needs, and what the tool costs to try.

Which OBD2 scanner should you bring to check a used car? It depends on how many cars you will look at and whether you will keep the tool. For one car and no phone, the Innova 5210 at $99.99 shows readiness, pending and permanent codes on its own screen. For several cars, BlueDriver Pro at $99.95 is the one, among the pages we saved, whose maker explains the cleared-code check to used-car shoppers, and the Veepeak OBDCheck BLE at $31.99 is the cheapest adapter if you accept a free third-party app. If you will own the car and want the car read on each drive you take with the app on your phone, PulsCar starts at $299.99 with an OBDLink MX+ included and ships to US addresses only. We make it, so weigh that reasoning against the sources below. No scanner proves a car is sound, and a clean scan is a reason to keep checking, not to stop.

The three situations are not a ladder. A $31.99 adapter is not a worse version of a $299.99 membership; they do different jobs, and a buyer who will plug in once on one driveway is better served by the cheaper tool. Inside each situation the order comes from the six things in the section below, not from price or brand.

How we checked, and where PulsCar stands

Sources. Every product fact comes from the maker's own published page, manual, help article, return policy or warranty, or from an official store listing, read on 22 October 2026 (the Autel manual and the FIXD FAQ comparison table on 8 October) and saved as dated text. Every legal and technical statement comes from the issuing body: the Environmental Protection Agency (EPA) and its eCFR text, the California Air Resources Board and Bureau of Automotive Repair, the Federal Trade Commission (FTC), the Department of Justice's National Motor Vehicle Title Information System (NMVTIS), and the National Highway Traffic Safety Administration (NHTSA), whose recall pages we could not read. We tested none of these tools on a car, and where a page does not print something we write "not printed" rather than fill the gap.

Prices and ratings. Competitor prices are those printed on each maker's own store, with the regular price where printed. PulsCar's prices come from the live checkout at get.pulscar.io and its Terms of Sale, read the same day. App ratings are quoted only with the count and the date, because a star average without its count is not information. We did not read or count individual reviews.

Where PulsCar stands. PulsCar's app works with the OBDLink MX+, and every PulsCar plan except Membership only includes one (two on Family). We have a commercial interest in that. Its claims here are limited to its checkout, Terms of Sale, scanner page, home page and store listings, and to the app's own code, which we read on 22 October 2026; we did not test the app on a car for this page. We say where it does not fit in the section on what it is not.

What we could not read. The FTC's consumer pages and the www.ftc.gov copies of its documents answered with HTTP 404, so we used the same documents from the FTC's own search host, search.ftc.gov: the Buyers Guide form, the dealer guide and a 2016 Commission statement. NHTSA's recall pages answered with HTTP 403 and we did not try to get around that. Ford's owner-guide documents were also blocked, so the car-maker statements on readiness come from Honda and Toyota manuals. A fuller list of absences is near the end.

What a used-car buyer needs from a scanner: six things

Most scanner reviews score speed, app polish and price. For a used-car check, six things matter more, because each one answers a question about what the seller did before you arrived. We applied them to every tool in the same way, using only what each maker prints.

1. Readiness status. (Also called I/M readiness, for inspection and maintenance programs.) Whether the tool shows each emissions self-test (a "monitor") as complete or not. After codes are cleared, the monitors go back to not complete. The next section explains why that matters and how far it can be trusted.
2. Pending codes. A code for a fault the car has seen but not yet confirmed as a problem. It does not turn the check engine light on, so it can show on a scan while the dashboard is dark. BlueDriver's help page puts it this way: "A pending code will not turn on your check engine light and indicates that a system on your vehicle is behaving abnormally, but not so much as to mean there is an actual problem."
3. Permanent codes. A special type that, per BlueDriver, "can not be cleared using a scan tool". A tool that cannot show them cannot see a clear that left a permanent code behind.
4. Counters since codes were cleared. Warm-ups, distance and engine run time since the last clear. These are the cleanest clue where the car supports them, and not every car does.
5. Freeze frame. The snapshot of the car's sensors at the moment a code was stored, which a clear erases. If a code was cleared, the snapshot goes with it, so an empty snapshot next to a "not ready" pattern is, in our reading, one more clue.
6. A warning that clearing resets the monitors. Not a feature of the car, but a sign that the maker has written for this use. It matters because the worst thing a buyer can do on a seller's driveway is clear a code to see what happens; the monitors reset, the evidence goes, and the seller's car now looks like it was cleared by the seller.

Two other considerations do not change the ranking: whether you need a phone (a handheld has its own screen) and what you can return if the tool does not work on the day.

The port and the law: why a car from 1996 or later has one

Every scanner on this page depends on a standard the federal government set. The California Air Resources Board's OBD II fact sheet says "All 1996 and newer model year gasoline and alternate fuel passenger cars and trucks are required to have OBD II systems." It adds that diesels follow a year later: "All 1997 and newer model year diesel fueled passenger cars and trucks are also required to meet the OBD II requirements." And it answers the question of whether the rest of the country is different: "The United States Environmental Protection Agency (U.S. EPA) requires all 1996 and newer model year passenger cars and trucks sold in any state to meet the U.S. EPA OBD requirements." The fact sheet also notes that a small number of 1994 and 1995 gasoline cars were equipped with OBD II, which is why the year alone does not settle it for an older car; the emission control label under the hood is the place to look.

Two practical consequences for a buyer. First, a car without OBD II may have no usable port at all, and no tool here will read it. Second, the port itself is evidence. EPA's inspection rule for states that test through the port, 40 CFR 85.2207, says "A vehicle shall fail the OBD test if it is a 1996 or newer vehicle and the vehicle connector is missing, has been tampered with, or is otherwise inoperable." A connector that looks damaged, moved or replaced is a question for the seller before you plug anything in.

Readiness monitors in plain words

A "monitor" is one of the car's own emissions self-tests, such as the catalyst, the fuel vapor system or the oxygen sensors. Each monitor runs only under particular driving conditions and reports back as complete or not complete. BlueDriver's help center defines the conditions this way: "A drive cycle is a set of conditions under which a vehicle must be driven in order for the vehicle to complete its emissions self-checks." A scanner reads the result, and shows it as "ready" or "complete" for a monitor that has finished and "not ready" or "not complete" for one that has not.

Why this matters to a buyer: when the codes are cleared, or the battery is disconnected, the monitors go back to not complete. Honda's 2024 CR-V owner's manual says "The readiness codes are erased when the battery is disconnected, and set again only after several days of driving under a variety of conditions." The Toyota Camry owner's manual we read says "When the battery is disconnected or discharged Readiness codes that are set during ordinary driving are erased." California's Bureau of Automotive Repair (BAR) states it as a rule for its inspectors: "Readiness monitors must be rerun after a repair activity like disconnecting a vehicle’s battery or replacing a defective emissions component."

That is the clue, and it is also the limit. Not complete does not mean the seller cleared a code. The EPA's June 2001 guidance to state inspection programs, EPA420-R-01-015, lists five reasons a car can arrive with self-tests incomplete. Besides "A recent resetting of the OBD system due to battery disconnection or replacement, or routine maintenance immediately prior to testing", it names a vehicle-specific OBD fault, a design anomaly, not enough of the right driving, and "A fraudulent attempt to avoid I/M program requirements by clearing OBD codes just prior to OBD-I/M testing (by, for example, temporarily disconnecting the battery)." BlueDriver's help page gives the same split from the scanner's side. A test listed as not complete can mean "Codes have been cleared recently, or the battery has been disconnected which resets all self checks" or "There is an issue with the vehicle that is preventing the test from completing". It also states the limit that matters most: "Unfortunately the standard OBDII smog check command is not able to distinguish between a test that is incomplete because it is in fact not complete, or a test that is incomplete because it has failed."

How many monitors may be unset before a car is turned away? EPA's own text, in 40 CFR 85.2222, allows an exception for "two or fewer unset readiness monitors" on model year 1996 to 2000 vehicles and for "no more than one unset readiness monitor" on model year 2001 and newer. BAR's table for California is stricter: for gasoline cars it lists any one monitor for 1996 to 1999 and only the evaporative system for 2000 and newer. These are inspection tolerances, not a promise about the car.

For the full reading of the four patterns, including what to do when monitors are ready but the counters are low, our used car inspection checklist walks the check step by step. Here we ask a narrower question: which tools show the screens at all.

Recently cleared codes: three clues a tool can show

A cleared code leaves three clues, and a tool is only as useful as the number of them it shows.

Clue one: the monitors. Covered above: not complete after a clear, ready again after enough driving. BlueDriver's help center says that when codes are cleared "all vehicle emissions tests are reset", and puts the buyer's use plainly: "If multiple tests under 'smog check' are listed as 'not complete' this may be an indication that codes have recently been cleared." Note the wording: may be, and multiple tests. A single incomplete monitor has other possible causes, and EPA's rule tolerates one on 2001 and newer cars (for gasoline cars California tolerates only the evaporative monitor, on 2000 and newer).

Clue two: the counters. Many cars also keep a count of warm-up cycles and distance since the codes were last cleared. BAR's workshop slides name them, "Mode $01 PID $30: Number of warm-up cycles conducted since DTCs were cleared" and "Mode $01 PID $31: Distance traveled since DTCs cleared", and say they are "Supported by most 2006+ diesel and most 2008+ gasoline vehicles". Another slide in the same deck says majority coverage by 2007 for gasoline, so the year is approximate. BlueDriver's help center is the one maker page we saved that frames this for a buyer: "When shopping for a used car there are two ways you can use your BlueDriver to check whether codes were recently cleared (either with a scan tool or by disconnecting the battery)". It lists warm-ups, distance and engine run time since the clear, and adds a caution about the last one: "codes may have been cleared two months ago but if the vehicle was driven five hours per week then this value will display 40 hours as opposed to 1,440 hours." A counter measures use since the clear, not calendar time, and a clear that happened long ago and many miles back looks like no clear at all.

Clue three: permanent codes. A permanent code is stored where a scan tool cannot erase it. BAR's newsletter says that unlike regular codes, they "cannot be reset by disconnecting the vehicle’s battery or cleared using an On-Board Diagnostic (OBD) scan tool"; the only way to clear one is to fix the fault and let the car re-run the test. BAR made them part of its Smog Check failure criteria for model year 2010 and newer in July 2019, and says the reading is ignored after 15 warm-up cycles and 200 miles since the car's information was last cleared. Innova's manual prints the same limit: "PDTCs will only be ignored if the vehicle has completed at least 15 warm-up cycles and driven at least 200 miles since its OBD information was last cleared." Support varies: BAR notes that some 2010 vehicles do not support them, and Autel's manual says its permanent-code function is "available for merely vehicles supporting the CAN protocols."

Can an OBD2 scanner show that a seller cleared the codes? It can show clues, never proof. After a clear, the monitors read not complete, the warm-up and distance counters restart where the car supports them, and a fault that lit the lamp may leave a permanent code. Which clue appears depends on the tool and on the car, and the table below shows what each maker prints. A tool that shows all three is the right one to bring. PulsCar's public pages print none of these screens, and its app code shows all three, with a connected scanner. But monitors set again after enough driving, a replaced battery looks like a clear, and a fault that never set a code leaves nothing to find. A bad pattern is a reason to ask and to pay for an independent inspection, not an accusation.

What each tool prints on those screens

Here is the six-things test from the section above applied to every tool. The right-hand count is of the six things (readiness, pending codes, permanent codes, counters since clear, freeze frame, and the warning that clearing resets the monitors) that the maker's pages and manual print; for PulsCar it is what the app's code shows. It is not a count of what the tool does on your car.

Four readings. First, the two handhelds print the most among the tools that need no phone. Innova's manual says "ERASE button – Erases Diagnostic Trouble Codes (DTCs), and “Freeze Frame” data from the vehicle’s computer, and resets Monitor status." and its text adds that permanent codes are not erased by it. Autel's readiness page carries a caution in capitals: "CAUTION - By clearing trouble codes you also clear the readiness status for the individual emission system readiness tests." Neither prints the since-clear counters; their readiness screens show monitor status "since DTCs cleared", which is a different thing from a count of warm-ups or miles.

Second, BlueDriver is the only tool, among the pages we saved, where the maker prints all six and speaks to a used-car buyer. Its help center states that "It is not possible to clear engine codes without resetting emissions tests using any scan tool", so there is no way around the reset. It also marks the limit of a pass: "BlueDriver will show the test results as reported by the vehicle, but can not guarantee that a vehicle will pass or fail its inspection."

Third, the OBDLink app is a capable reader that does not print the same story. Its pages say the Monitors screen "shows you whether your vehicle is ready for emissions testing" and list warm-ups, distance and engine run time since codes were cleared among the PIDs a car may support. They do not print pending codes, permanent codes, or a warning about clearing. That describes the pages we saved; the app may show more than they say.

Fourth, FIXD puts its emissions check behind its paid tier, and a cheap adapter depends on the app. FIXD's pages say the free app reads and clears codes and gives a severity for each. On the FAQ's comparison table, which we saved on 8 October because today's read of that page returned a shorter version, "Pass emissions the first time with Emissions Precheck" is a Premium row (we read it as a readiness check), and so is "Get unlimited Used Vehicle History Reports". Pending codes, permanent codes, the counters and freeze frame appear nowhere on the pages we saved, and the FAQ prices Premium at $99.00 per year. The FAQ also lists checking a used car before purchase among the app's uses without saying which screens it shows, so on the printed record we could not confirm the screens a used-car buyer needs. A Veepeak adapter prints I/M readiness and freeze frame support, and Veepeak says what you get "mainly depends on the chosen App". Car Scanner's Google Play page lists "Check if your car is ready for emission tests."; its App Store entry says the app is free "but to unlock all the features, a one-time purchase or a subscription is required".

Situation one: one car, no phone, so a handheld reader

Two handhelds are on the shelf, and both print what a buyer needs on the codes. Neither needs a phone, an app or a Bluetooth pairing in a stranger's driveway.

Innova 5210, $99.99 sale ($119.99 regular). The page says the 5210 diagnoses the engine and ABS modules. Its user's manual describes an I/M readiness function that "displays which vehicle particular Monitors have or have not run", with a choice between "Since DTCs Cleared" and "This Drive Cycle", and a code-type field that shows Stored, Pending or Permanent. The manual states that the ERASE button erases codes and freeze frame data and resets monitor status, that permanent codes are not erased by it, and gives the advice a buyer should take as a rule on someone else's car: "If you plan to take the vehicle to a Service Center for repair, DO NOT erase the codes from the vehicle’s computer." The page says "Updates are free. And there are no subscriptions." and calls the companion RepairSolutions2 app "100% optional and free to use". The return window is 30 days from delivery for a full refund minus shipping, with the product new or unused; the warranty is one year. It "will NOT work outside of the United States and Canada", and the page warns that for 2018 or newer Fiat Chrysler vehicles that need secure access its features are limited. Its counter is not on the printed record: we found no display of warm-ups or distance since the clear in the manual.

Autel AutoLink AL619, $99.99 limited sale. The page says it detects faults on ABS and airbag (SRS) systems as well as OBD II, and the manual's readiness page offers "Since DTCs Cleared" and "This Drive Cycle" views, warns that clearing codes clears the readiness status, and says a "NO" result "does not necessarily indicate that the vehicle being tested will fail the state I/M inspection." Pending codes are supported, and permanent codes only on CAN vehicles. Two limits matter for a buyer. The page says the tool "can read and clear OBD codes on all post 1996 domestic, post 2006 European and post 2009 Asian vehicles", so a 2004 import may fall outside it, and the page adds "AL619 is not compatible with all vehicles, please contact us for a check before placing an order." The page's feature list says "Compatible with domestic, Asian and European vehicles, 1996 and newer", a wider range than the year list above; ask Autel before buying for an older import. The page prints no phone app and no Bluetooth. Autel offers a 30-day return policy, with return shipping paid by the buyer when the return is the buyer's choice, and a one-year warranty.

Our rank: Innova first for a simple one-car check, because it prints a manual line on every code type and a free-update promise; Autel, which prints the code-type lines too, when you also want ABS and airbag codes and the car is within its year list.

An unavoidable limit for both, from Innova's FAQ: "No, OBD2 scanners require the vehicle to be able to start or at least crank." A seller who says the car "just needs a battery" is telling you the scanner will not help yet.

Situation two: several cars and a phone

Three of the ranked tools use a phone. Their prices are $99.95, $139.95 and $31.99, and the difference between them is mostly what the maker prints and what the app costs.

BlueDriver Pro, $99.95 ($119.95 regular). The page says "Zero Subscription Fees or Add-ons"; the sensor plugs into the port, and the app needs an account and is listed as free on the App Store. It is the one tool on the shelf, among the pages we saved, whose maker prints all six things and speaks to a buyer: the help center's cleared-code article, the explanation of confirmed, pending and permanent codes, the smog-check results page, and the note that clearing cannot avoid resetting the tests. It lists warm-ups, distance and engine run time since the clear, where the car reports them. It also has a recall caution a buyer should read: "The BlueDriver app will display all recalls associated with a vehicle's year and model, but can not confirm whether the recall applies to your specific vehicle." The return window is 180 days from confirmed delivery for products bought directly from BlueDriver, with a return authorization, and the warranty is one year. On the stores, the app is 4.6 on the App Store and 3.5 on Google Play (counts in the ratings table below).

OBDLink MX+, $139.95. A Bluetooth adapter (the page prints Class 2 Bluetooth v3.0 and a physical Connect button that has to be pressed to pair) with a free app on iOS, Android and Windows. OBDLink says the app and its OEM add-ons are free to MX+ users, though third-party apps may cost extra. The Monitors screen "shows you whether your vehicle is ready for emissions testing", and the counters are in its PID list. It prints no pending or permanent code screen and no clearing warning on the pages we saved. The page promises "an unconditional 180-day money-back guarantee, and a 3 year warranty." We make PulsCar, whose app runs on this adapter; you do not need PulsCar to benefit from it.

Veepeak OBDCheck BLE, $31.99 ($34.99 regular). The page says it supports Bluetooth LE and Classic Bluetooth, works with iOS and Android, and has no official app: "A third party OBD2 app is required." It recommends the free Car Scanner ELM OBD2 for most users. The product page's FAQ names the apps that do not work with the adapter: "These Apps are incompatible: Bluedriver, FIXD, Carly, MHD, xHP, ProTool, bootmod3, Multiecuscan, Techstream, VCDS, etc." The user instructions give a one-year replacement warranty. The product page prints no return window and we did not open the separate return page, so ask the seller before you order. Car Scanner is 4.7 on Google Play from 367K reviews, lists ads and in-app purchases there, and on iPhone is free with one-time-purchase or subscription unlocks.

Our rank: BlueDriver Pro first, because it is the only tool, among the pages we saved, whose pages tell a buyer what to look for and print or explain all six things, at a price $40 below the OBDLink MX+. OBDLink MX+ second, because it is a better long-term adapter and the one PulsCar uses, but its pages are thinner on the buyer's screens. Veepeak third, as the budget route, with the honest caveat that the screens you get depend on a third-party app you choose, and the lowest printed score of the three.

Situation three: the car you will own

A used-car scan is a snapshot of a car you do not know. Once you own the car, the question changes from "what did the seller do?" to "what is this car doing now?" Two tools on this page are built for that job: PulsCar, and FIXD by its own description.

Does PulsCar help when you check a used car, and what does it cost? Partly, and a cheaper tool does the one-time job. PulsCar's app, in its own code, reads stored, pending and permanent codes, shows each readiness monitor as Ready or Incomplete, and shows distance, time and warm-ups since codes were cleared, with a connected OBDLink MX+. But the One Year plan costs $299.99 against $99.95 for BlueDriver Pro, and is priced as a year of ownership. Its checkout also pitches it for checking a car before you pay; we vouch only for the screens we read in the app's code. Its strength comes afterwards: the membership includes the scanner, one payment covers twelve months, and the app reads the car on every drive while your phone is in the car with the app on. Plans are on the checkout; we make PulsCar, so weigh this against the sources.

What PulsCar's pages and code support. The live checkout says every plan except Membership only includes an OBDLink MX+; the Terms of Sale say the membership starts on the day you activate the serial number in the app, and the scanner page says there is no monthly plan. The plans, as read on 22 October 2026: One Year $299.99, Two Years $499.99, Family $549.99 for two scanners and two vehicles, and Membership only $199.99 for owners of an MX+, with the serial number emailed within minutes and nothing shipped. Nothing renews automatically; after the first term, renewal is $179 a year per car and covers app access only. Two Years costs $21 more than One Year plus one renewal ($499.99 against $478.99), so it is a convenience, not a discount. The Terms of Sale give a full refund before the scanner ships and 30 days after delivery to ask for a refund (30 days from the serial-number email on Membership only). While you drive with the app on, its code raises a pull-over alert for coolant at 118 C (244 F) or battery voltage under 11.8 V.

What the app's code shows for the buyer's screens. We read the app's source on 22 October 2026. The Terms and the scanner page say diagnostics pause without an active membership while the safety core (SOS, critical alerts, current fault codes, battery voltage) stays open; the app's code leaves the whole codes screen and the whole live screen, which holds the Ready tab, open to non-members, and we did not test that on a phone. On connection the app reads stored, pending and permanent codes and the check engine lamp state. A "Ready" tab lists each monitor the car reports as "Ready" or "Incomplete" and says incomplete monitors finish after about twenty minutes of mixed driving (the app's wording; Honda's manual says several days, so treat twenty minutes as the best case). A "Since codes cleared" group shows distance with the lamp on, time with the lamp on, distance since clear, time since clear and warm-ups since clear, each marked "not on this car" when the car does not support it. When you press clear, the app first says "This clears codes AND readiness monitors". It shows no freeze-frame screen that we found. These are code facts, not a test on your car.

Where it does not fit the buyer's day. If the OBDLink MX+ ($139.95, free US shipping, no delivery time printed) can reach you before the viewing, you can have the hardware first and add Membership only ($199.99) after: $339.94 before tax, or $39.95 more than One Year. If it cannot arrive in time, a same-day handheld is the tool for the viewing. The free sound check, covered near the end, needs no scanner and no card.

FIXD Sensor, $59, for comparison. FIXD's home page says you can clear check engine lights with a button, and its FAQ says the free app reads codes and tells you the severity of each. Its pages call out "REAL-TIME MONITORING". The FAQ's comparison table, saved on 8 October, lists Emissions Precheck and unlimited used-vehicle history reports as Premium rows, so FIXD does address a buyer, behind a subscription its FAQ prices at $99.00 per year. For the free app, the pages we saved print no pending, permanent, counter or freeze-frame screen, so we could not score it on the printed record. Our comparison of its billing is in FIXD versus PulsCar, and our guide to what to buy instead of it is FIXD alternatives.

What PulsCar is not

Everything a buyer should weigh against PulsCar, once, in one place. Scanners ship to US addresses only, so a buyer outside the United States cannot order the plans that include the hardware. The up-front price is higher than a bare reader: $299.99 for One Year against $99.99 on sale for the Innova or Autel readers, or $200.04 more than BlueDriver Pro. It is not a one-time-check tool, and the plans that include a scanner ship within seven days, so they will not arrive for this weekend's viewing. The app needs the OBDLink MX+ and no other adapter; Membership only works with the MX+ and not with the MX, LX, EX or CX. It does not estimate repair prices; the checkout says "PulsCar does not estimate repair prices." Its readings are information, not a diagnosis, and for brakes, steering or overheating it tells you to stop and have the car inspected in person. It records trips and watches the car when your phone is in the car with the app on; the checkout says "The scanner doesn’t record on its own", and on iPhone the app must be open when the drive starts, because the background service that starts recording by itself is Android-only in the app's code. It is not an emergency service. And its store listings are young: the App Store lookup shows no ratings, and the Google Play listing shows a 5+ downloads figure and no star rating, so there is no store history to lean on.

Store ratings, with counts and dates

The App Store figures come from Apple's public lookup and the Google Play figures from each listing, all read on 22 October 2026. A star average without its count is not information, and the counts run from 12,911 ratings to 367K reviews. The right-hand column gives the App Store figure first and the Google Play figure second.

Three readings. The iPhone and Android stories differ for BlueDriver by more than a point, and for FIXD by 0.6 of a point; an owner should read the number for their own platform. PulsCar has no store record yet, which is a fact about its age, not a verdict.

What it costs, and what you can return

Printed prices on 22 October 2026, from the cheapest tool to the dearest plan (sale prices where a sale was running: Innova's regular price is $119.99, and Autel's is a limited sale). The right-hand column is the up-front cost of the tool; the note carries what a return costs you if the tool does not work on the day.

Two sentences of arithmetic. BlueDriver Pro costs $40 less than the OBDLink MX+, and the Veepeak adapter costs $67.96 less than BlueDriver Pro, before any paid app. PulsCar's One Year plan costs $200.04 more than BlueDriver Pro, which buys a scanner you keep and twelve months of the app reading each drive you take with the app on your phone. The refund clocks matter because the day you most need a tool to work is the day of the viewing: BlueDriver and OBDLink print 180 days, Innova, Autel, FIXD and PulsCar print 30, and Veepeak's product page prints none.

What no scanner can show: six gaps and the official tool for each

A scanner reads one thing, the car's computer, at one moment. Everything below is outside it. The right-hand column names the tool that does answer the question.

Title brands: salvage, junk, flood. This lives in the title record, and the page does not describe NMVTIS as an accident-history report. The Department of Justice's NMVTIS consumer page says the system lets a buyer find information on "the vehicle's title, most recent odometer reading, brand history, and, in some cases, historical theft data." A "brand" is the label a state gives a vehicle such as junk, salvage or flood. The same page warns that a clean search is not a guarantee: "consumers should be aware of the possibility that a search may yield a false negative indication". Reports come from the approved providers listed on the provider page. A scanner knows none of this.

The odometer. Many scanners can show a mileage figure the car reports, and OBDLink lists "Vehicle Odometer Reading" among the PIDs a car may support. We found no maker page that says the figure proves the real mileage, so we do not treat it as proof. The document is the odometer statement. Under 49 CFR 580.5, "the transferor shall disclose the mileage to the transferee on the physical or electronic title" or on the document used to reassign it. Exemptions are by vehicle age (§ 580.17; our checklist covers them). A seller who will not sign a mileage statement on a car that needs one is telling you something no scanner can.

Open recalls. The FTC's Buyers Guide form, which a dealer posts on a used car, says "To check for open safety recalls, visit safercar.gov." The reason to do it yourself is in a 2016 Commission statement: "Federal law requires that all new cars sold in the United States be free from recalls, but it does not prohibit auto dealers from selling used cars with open recalls." That is the 2016 text; we did not find a later change on the pages we read, and NHTSA's own recall page would not load for us (HTTP 403), so use the VIN lookup there and read what it says. A scanner app may list recalls by year and model, as BlueDriver's does, but BlueDriver says plainly it can not confirm one applies to your VIN.

Worn parts. The FTC's Buyers Guide carries a list of major defects that includes brake lining thinner than 1/32 inch, a rotor that is too thin, tread depth under 2/32 inch and a steering wheel with too much free play. None of that is on the diagnostic bus. The same form tells the shopper "ASK THE DEALER IF YOUR MECHANIC CAN INSPECT THE VEHICLE ON OR OFF THE LOT." Our used car inspection checklist walks the physical check, and the car inspection cost guide prices a professional one.

A tailpipe test. BlueDriver says that where a region samples the tailpipe, "this can not be assessed in advance using a scan tool."

Faults that never set a code. That last gap has a number from our own published work, and we do not re-run it here.

Faults that never set a code: the count we already published

Our page FIXD versus PulsCar counted every complaint the National Highway Traffic Safety Administration publishes for ten high-volume nameplates, model years 2015 to 2022: 39,355 complaints. Of the 4,847 in which an owner described a sound, 3,838, or 79%, mention no light, no code and no scan. Those are complaints, not failure rates, and an owner who does not mention a lamp may simply not have thought to; the page states the limits in full. A clean scan therefore leaves open the faults owners describe by sound, which is where a test drive and, with permission, a listen at the engine do the work. Our best OBD2 scanner page shows the same count from the scanner shopper's side.

On the seller's driveway: what to do with the tool

This is our advice, built on the sources above, not a regulation.

1. Ask before you plug in. It is the seller's car and the seller's port. Say what you will do: read codes and screens, change nothing.
2. Read; do not clear. Clearing resets the monitors on any tool, per BlueDriver, and Innova's manual tells a user planning a repair visit not to erase the codes, because the information that helps the technician goes with them. A buyer who clears a code to see whether it comes back has destroyed the evidence and cannot say who cleared it.
3. Photograph each screen. Readiness, pending, permanent, the counters if the car shows them, and freeze frame. The photographs are what you will show a mechanic or use if you decide to walk away, and they save you from remembering a number wrongly.
4. Note what is "not on this car". A counter the car does not support is a blank, not a clean result.
5. Look at the port first. A connector that is missing, tampered with or otherwise inoperable is something EPA's 2001 inspection guidance says a state should fail on a 1996 or newer car. Ask why.
6. Scan before and after the test drive. Compare the two reads and note anything that changed. Some monitors need a cold start and specific driving that a short test drive will not give, and Honda's manual says the readiness codes return only after several days of driving following a battery disconnection, so one that flips to ready during a few minutes' drive is worth a question, not a verdict.

The traps: three ways a careful buyer still gets it wrong

Trap one: reading "ready" as "sound". All monitors ready means the car has completed its self-tests since it was last reset, and nothing more. Honda's 2024 CR-V manual says that after a battery disconnection the readiness codes are "set again only after several days of driving under a variety of conditions", so a car cleared a week before you arrived can show ready by the time you read it. The counters keep counting from the clear and a permanent code stays until the fault is fixed and the car has re-run the test, so they are the clues that do not fade the way the monitors do, where the car supports them. A pass on all of them is a lack of evidence, not evidence.

Trap two: reading "not ready" as proof of fraud. The EPA's own list gives five reasons a car arrives with self-tests incomplete, and only one is fraud; a replaced battery and plain lack of the right driving are others. BlueDriver says the standard smog-check command cannot tell a test that has not run from one that has failed. Ask when the battery was replaced, ask for the receipt, and let the independent inspection settle it.

Trap three: buying the tool and skipping the inspection. A buyer with a $99.95 tool and a clean scan still has not looked at the brakes, the title, the recalls or the underbody. The FTC form tells shoppers to ask the dealer whether their own mechanic can inspect the car; the scan is the first step toward that decision, not a substitute for it.

Three composite situations, decoded

These are composite scenarios, not individual customers. Each is built only from facts already on this page.

Scenario one: the weekend of three cars. A buyer brings BlueDriver Pro, $99.95, and a phone. On the third car, the seller calls it a daily driver, but several monitors read not complete and the warm-up and distance counters are very low. The seller says the battery was replaced last month. EPA's list names a battery replacement as one of five possible reasons, so the buyer does not accuse anyone. They ask for the receipt, photograph the screens, and book an independent inspection before any money moves.

Scenario two: one truck, one handheld. A buyer looking at a single late-model US truck brings the Innova 5210, $99.99. The screen shows a pending code, which they photograph to ask about, and all monitors ready. They keep the screen photographs and take the truck to a mechanic they chose, who reports thin brake pads and a leak the scanner could not have shown. They negotiate the price.

Scenario three: after the purchase. A buyer who has signed the paperwork wants the car read on each drive they take with the app on their phone. They order PulsCar One Year at $299.99. Meanwhile a ticking noise on a cold start bothers them. They film 30 seconds of the engine with the free sound check, and the report says it is inconclusive, so they record it again. A squeal from a front wheel they do not film; they have the brakes inspected first. What would have gone wrong: ordering a membership to read one code on a car they had not yet bought.

Where a free sound check fits, and where it does not

This is our side of the page, and it concerns the one PulsCar product that costs nothing. PulsCar's free sound check asks you to film your engine running for 30 seconds and returns a report by email in about ten minutes. The home page states the terms plainly: "No payment, no card, no subscription." If a clip cannot support a confident verdict, the report says "inconclusive", and you can record again.

On a used-car visit it is a helpful extra and not a replacement for anything above. It needs no scanner, so it works on a car whose port you cannot use or on a day you left the tool at home, and with the seller's permission you can film the engine on the driveway and read the report later. It reads no trouble codes, clears no lights, shows no readiness status and no live data. It listens to an engine; it does not see a title, an odometer, a recall or a worn brake pad. The checkout's wording for the in-app Sound Check is that a result is "a probability, not a verdict", with accuracy depending on recording conditions; we apply the same caution to the free check.

Two limits belong with it. A sound that only appears while braking or turning on the road may not be in a clip filmed at the engine. And for a noise from the brakes, the steering or a wheel, or for any red or flashing warning light, have the car inspected before you do anything else, and do not buy that car on the strength of a recording. A flashing check engine light is the one rule on this site: pull over safely, switch the engine off and have the car towed; the only exception is a shop within two or three miles, reached gently, under 40 mph and with light throttle, and that is our advice, not a manufacturer's. On a test drive in someone else's car, do not use the exception: stop somewhere safe, switch the engine off and hand the keys back.

What we looked for and did not find

A page that says nothing is a different fact from a page that says no, so the absences are part of the evidence.

• A maker page, other than BlueDriver's, that tells a used-car shopper how to check for cleared codes. We searched the Innova, Autel, OBDLink, Veepeak, FIXD, Car Scanner and OBD Fusion pages we saved. FIXD's home page links used-car buying guides we did not read, so FIXD may cover this there.
• Warm-up and distance counters in the Innova and Autel manuals. Their readiness screens show monitor status since the codes were cleared, which is a different thing.
• Pending or permanent code screens on the OBDLink pages we saved, and pending codes, permanent codes, counters or freeze frame on the FIXD pages.
• A warning that clearing resets the monitors on the OBDLink, FIXD, Veepeak, Car Scanner and OBD Fusion pages. Innova, Autel and BlueDriver print one.
• The federal text of the 1996 OBD requirement. The sections of 40 CFR Part 86 we tried were not retrievable, so we rely on the California Air Resources Board's statement of the EPA requirement and on EPA's 2001 guidance.
• NHTSA's recall lookup (HTTP 403) and the FTC's consumer pages and www.ftc.gov document copies (HTTP 404), so those statements come from FTC documents read at search.ftc.gov. Ford owner-guide readiness text (HTTP 403), so the car-maker statements are Honda's and Toyota's.
• A Veepeak return window on the pages we saved.
• Any maker or regulator statement that a scan proves a used car is sound, or that a scanner reading proves the true mileage. None of the pages we read says so.

Your action plan: before you buy a tool, at the car, and after the purchase

Before you buy a tool

1. Decide the situation. One car and no phone: a handheld. Several cars: BlueDriver Pro or an adapter. You will own the car and want the car read on each drive you take with the app on your phone: PulsCar. The table at the top has one pick for each.
2. Check the car's year. OBD II is required on 1996 and newer gasoline cars and 1997 and newer diesels, per the California Air Resources Board. Check the tool's own coverage: the Autel page lists post 1996 domestic, post 2006 European and post 2009 Asian for reading and clearing (and also says 1996 and newer), and the Innova works in the United States and Canada only.
3. Look up the car before the visit. Recalls by VIN at NHTSA, and a title history through an NMVTIS-approved provider. Both are free of the scanner and both answer questions it cannot.
4. Check delivery. A tool you can pick up the same day will be in your hands at the viewing; a mailed scanner will not.

At the car

1. Ask the seller before you plug in, read without clearing, and photograph each screen.
2. Work through the readiness monitors, then pending and permanent codes, then the counters where the car shows them; our used car inspection checklist gives the order and the four patterns.
3. Scan before and after the test drive, and write down anything that changed.
4. If anything is off, or the price is high enough that a hidden fault would hurt, pay for an independent pre-purchase inspection before any money moves. Our car inspection cost guide prices it.

After the purchase

1. Decide inside the tool's return window, not after it: 180 days at BlueDriver and OBDLink, 30 at Innova, Autel, FIXD and PulsCar.
2. If you will keep reading the car, the neighbours are our best OBD2 scanner page, BlueDriver alternatives, the OBDLink MX+ review and the diagnostic cost guide.

Sources and documents

Every statement above comes from the pages below, read on 22 October 2026 and saved as text, except where a date is given. Prices, ratings and counts are as printed that day.

• Environmental Protection Agency: 40 CFR Part 85, Subpart W (85.2207 and 85.2222), EPA420-R-01-015, OBD checks in I/M programs, June 2001
• California: Air Resources Board, OBD II systems fact sheet; Bureau of Automotive Repair, OBD test reference, permanent codes, Fall 2019 and permanent-code workshop slides, 2018
• Federal Trade Commission: Used Car Rule, 16 CFR Part 455, the Buyers Guide form, the dealer's guide to the rule and the Commission's 2016 statement on recall advertising
• Department of Justice, NMVTIS: consumer page, approved providers
• NHTSA: Odometer Disclosure Requirements, 49 CFR Part 580
• Car makers: Honda owner's manual, testing of readiness codes; Toyota Camry owner's manual
• Innova: CarScan Advisor 5210, return policy, warranty, 5210 user's manual
• Autel: AutoLink AL619, AL619 user manual, return policy, warranty
• BlueDriver: product page, refund policy, help center articles on checking whether codes were cleared recently, confirmed, pending and permanent codes, smog test results, resetting emissions tests, completing drive cycles and recalls
• OBDLink: MX+, OBDLink app, FAQ, warranty
• Veepeak: OBDCheck BLE, user instructions
• FIXD: home, FAQ, features, returns and warranty
• Google Play listings: BlueDriver, OBDLink, FIXD, Car Scanner ELM OBD2, PulsCar: Car Health Monitor
• App Store data: Apple's public lookup for BlueDriver, OBDLink, FIXD, Car Scanner ELM OBD2 and PulsCar
• PulsCar: checkout at get.pulscar.io, Terms of Sale, scanner page, home page and free sound check, FIXD versus PulsCar (the 39,355-complaint count), and the app's own source code, read on 22 October 2026 (no public URL)
• Attempted, access blocked, not quoted: nhtsa.gov/recalls (HTTP 403), the FTC's consumer pages on buying a used car and the www.ftc.gov copies of its documents (HTTP 404; the documents were read from search.ftc.gov instead), Ford owner-guide documents (HTTP 403)

Methodology. We read each page on 22 October 2026 and saved its text with the date. Every price, rating, review count, rule, date and quotation on this page was checked against those saved pages, and every quotation in italics is word for word from one of them. Government statements are quoted from the issuing body or from the eCFR edition of the federal text. We tested no scanner on a car and we did not read or count individual reviews. PulsCar's claims are limited to its checkout, Terms of Sale, scanner page, home page and store listings, the app's own code, and Apple's public lookup for the App Store rating count. Where a page could not be read or printed nothing, we say so in the section above. The three composite situations are illustrations built from facts on this page; they are composite scenarios, not individual customers.

Prices verified: competitor prices as printed on each maker's own store and PulsCar prices on its live checkout, 22 October 2026. Technical documents verified: regulations, manuals, help articles, car-maker manuals and store listings, 22 October 2026 (Autel manual and FIXD FAQ comparison table, 8 October 2026). Written by PulsCar, which makes the membership and the free sound check.