P0430 Code in 2026: What Bank 2 Means, and Five Checks Before You Buy a Converter

P0430 is a verdict on two sensor readings taken from one row of cylinders. The computer watches oxygen before and after the catalyst on bank 2; when the "after" signal starts to look too much like the "before" signal, it decides that catalyst is not doing its job.

Plenty of things make that comparison look bad while the converter is fine, and manufacturers say so in writing. Honda's bulletin 17-036 for the 2016 Pilot opens by stating that "the PCM software may misinterpret sensor inputs as a deteriorated catalytic converter." Ford went further and recalled 319,160 Expeditions because their diagnostic system "may falsely set the catalytic converter Diagnostic Trouble Code (DTC) P0430."

By the end of this guide you will know which side of your engine bank 2 is, which of five routes your P0430 belongs to, what proves it, and what each one costs — from a $0 VIN check to a $4,500 dealer converter. Claims marked 🟢 rest on a document in Sources, opened and read; ⚪ marks estimates and owner reports.

I built Pulscar — an AI tool that reads car problems from a 30-second recording — after a $380 "full diagnostic" in Phuket in 2025 led to roughly $6,000 over six months across several shops, and the sound never went away (the story is on the About page).

First: which side is bank 2 on your engine?

One rule overrides everything below: fix what feeds that bank before you replace that bank's converter. A misfiring or oil-burning row of cylinders kills a new converter the way it killed the old one, and the second one is rarely covered by anybody. Three splits remove most of the remaining confusion.

Can your engine even set it? A bank is a row of cylinders. A four-cylinder engine has one row, so it has only bank 1 and cannot set P0430 — if a reader shows it on an inline four, suspect the reader or a generic definition table before you suspect the car. A V6, V8 or flat engine has two rows, and on almost all of them each row gets its own catalyst. Bank 1 is the row containing cylinder number 1; bank 2 is the other one.

Which physical side is that? There is no universal answer, and this page will not invent one. Manufacturers state it per engine family and they genuinely disagree. Honda's owner notification letter of 29 March 2021 spells it out for their V6: "P0420 (rear bank catalyst system efficiency below threshold [bank 1])" and "P0430 (front bank catalyst system efficiency below threshold [bank 2])." On a transverse Honda V6, bank 2 is the bank nearest the radiator. Ford's 22M06 labor table for the 3.7L Explorer, by contrast, prices "Replace Rear (RH) Catalytic Converter" at 2.2 hours and "Replace Front (LH) Catalytic Converter" at 1.7, and never says which is which bank. Get the answer for your engine from the manufacturer's repair information or a dealer, not from a generic diagram.

P0430 alone, or with friends? A misfire code (P0300 to P0306), an air-fuel variation code (Honda's P219A and P219B), a lean or rich code (P0171, P0172), a fuel pressure code, or P0420 itself stored beside P0430 almost always outranks it. In our complaint reading, the codes stored alongside P0430 were the best single predictor of what the bill turned out to be.

The 10-minute driveway protocol

1. Read every code and save it before anyone clears anything. A $20 to $40 Bluetooth reader gives you stored, pending and history codes plus the freeze frame. Clearing first throws that away — and on some cars it closes a free repair.
2. Write down whether P0420 is stored too. Both banks at once moves you off the converter theory.
3. Watch the dashboard while the engine idles. A flashing light or a shaking engine means a live misfire: Route 2, today.
4. Start the car cold and listen along the exhaust, one side at a time. A tick or puff that fades within a minute, on one side only, is a leak candidate: Route 1. Record 30 seconds from each side.
5. With the engine off and cool, tap both converter shells. A gravelly rattle inside one shell is broken substrate; a tinny buzz from the outer skin is a heat shield.
6. Run the VIN through NHTSA's recall lookup and your manufacturer's owner site. On several cars in this guide that step ends the story at $0: Route 4.
7. Write down the odometer and the in-service date. Under 8 years and 80,000 miles the federal emissions warranty covers the converter — and P0430 owners land inside that window far more often than P0420 owners do.

Ten minutes, a cheap reader and a phone, and you have done most of what an $80 to $200 diagnostic fee buys. What a diagnostic should cost covers the rest.

The price ladder: read it from the bottom up

Read it from the bottom up: the last line and the lines above it are frequently the same part, separated by a VIN, an odometer and a diagnosis nobody bothered to do.

Your number, by what you drive

Two rows break the pattern. On the Expedition and the F-150 hybrid, Ford's position is that the warning itself may be wrong. On the 2025 Pilot there is no fix yet at all — the manufacturer is still gathering evidence, which is the earliest stage of a document ever becoming a campaign.

The five routes, cheapest first

Route 1 · One side only — a leak ahead of the bank 2 rear sensor

The tell. A tick or puff on a cold start that quiets as the exhaust warms, plus soot streaks at a flange or clamp — and, the part that matters here, on one side of the engine only. Often after a muffler, hitch, manifold or pipe job on that side.

What it actually is. A leak between the engine and that bank's rear oxygen sensor lets outside air into the exhaust, and the sensor's reading stops meaning what the computer thinks it means. Because each bank has its own pair of sensors, a leak on one side sets only that side's code — which is why a lone P0430 is worth crawling under the car for. GM's PIP5110C tells technicians with a lone catalyst efficiency code to check for "a possible leak in the exhaust system" behind the relevant downstream sensor, and adds: "This repair must be attempted before considering the replacement of a catalytic convertor." Subaru's 09-110-23R puts a leak inspection at step 4, ahead of any decision about exhaust pipes.

The cheap cause that gets skipped. Clearance and hardware. The same GM document tells technicians to check exhaust clearance where an aftermarket bed or hitch has been fitted, and to fit a new clamp. A reused flange bolt, a gasket nobody replaced, a heat shield rubbing a pipe: one-side problems that cost tens of dollars.

Fix it yourself — find the leak, do not chase it with sealant. Cold engine, parking brake on. Have someone start it while you listen along the exhaust from the front wheel back on each side separately, look for soot tracks at every flange, and hold a hand a few inches from joints — never on them — to feel for a pulse. Record 30 seconds at each suspect joint. The honest limit: use stands, never a jack alone, and a cracked flex section or manifold is welding work.

Where this does not apply. A tick from the top of the engine that does not fade as the metal heats is valvetrain or injector noise; the ticking guide sorts those out.

At the shop — say this: "P0430 with a cold-start tick on one side. Before any converter quote, smoke- or pressure-test the exhaust on that bank from the manifold to the rear oxygen sensor, and show me any leak you find."

Route 2 · Bank 2 is being fed something — injectors, misfire and oil

The tell. Hesitation, a stumble, a rough idle, a shudder on light throttle, a raw fuel smell, smoke, or a flashing light. On the reader: P0300 to P0306, P219A or P219B on a Honda V6, P0171 or P0172, or a fuel pressure code such as P0087 beside P0430.

What it actually is. A cylinder that does not burn its fuel properly pushes unburned fuel into that bank's exhaust, and the catalyst burns it instead — which is how converters overheat and melt. Oil does the slower version, coating the catalyst until it cannot work. Honda documented exactly this chain on its V6 and then paid for it: bulletins 19-072 and 19-073, both titled "MIL Comes On with DTC P0430 or P0430 with P030X, P219A, P219B," with and without a software update, were folded into 20-100, and the owner letter of March 2021 extended fuel injector coverage "to 10 years from the original date of purchase or 150,000 miles, whichever comes first" for "the original owner and any subsequent owners." The dealer procedure runs a cylinder air-fuel test and replaces the injectors that fail it. Owners in our set describe that test finding cylinders 4 and 5, or 1 and 6, or 2, 5 and 6 running rich.

The cheap cause that gets skipped. The history codes and the freeze frame. In our reading of all 106 complaints, 51 — 48.1% — turned out to be an engine or fuelling fault feeding that bank, against 12 where the converter itself was the answer with no upstream cause named. What separates those outcomes is usually already in the car: a stored P219B, a misfire count on one cylinder, a fuel trim figure. A shop that quotes a converter without printing those has not diagnosed anything.

Fix it yourself — prove where the misfire lives. On an engine with individual coils, note which cylinder the misfire code names, swap that coil with its neighbor, clear the misfire counter and drive. If the misfire follows the coil, the coil is the part. The honest limit: a cylinder air-fuel test, direct-injection injectors and compression testing are shop work. The flashing light guide walks through the rest.

Where this does not apply. A misfire that has been repaired and a P0430 that stays can mean the misfire already damaged that catalyst: Route 5, but only with the cause fixed first.

At the shop — say this: "P0430 with a misfire history. Print every stored, pending and history code plus the freeze frame, run a cylinder air-fuel test on bank 2, and check this VIN for an injector extension. Do not quote a converter until the fuelling is fixed and the catalyst monitor has run again."

How do you tell a broken converter from an exhaust leak without lifting the car? By ear, because the cheap and expensive causes of this code sound nothing alike. Broken catalyst substrate is loose material inside a steel shell, so it rattles: a dry, gravelly shake from under the middle of the car, loudest at idle and when the cold shell is tapped. An exhaust leak is gas escaping at a joint, so it ticks or puffs in time with the engine, loudest when the metal is cold and quieting as the joint expands. Film 30 seconds of the engine running, parked, on a cold start, and Pulscar's free check returns a likely cause, a severity and a repair-cost estimate, or "inconclusive" — it does not decide whether the car is safe to drive. Free, no card, about ten minutes, and the report arrives by email. More rattles are in the rattling noise guide.

Route 3 · The car only thinks bank 2 failed — software, monitors and drive cycles

The tell. A lone P0430, or P0430 and P0420 together, on a smooth engine with normal power, no smell and no rattle. Often the light comes and goes, or returns a few weeks after being cleared.

What it actually is. Every piece of the measurement can fail without the catalyst failing, and on this code manufacturers have said so at enormous scale. Ford's emission recall 24E13, dealer letter dated 16 April 2025, covers 2018-2021 Expedition vehicles with the 3.5L EcoBoost built at Kentucky Truck between 14 March 2017 and 27 December 2021 — a US population of 319,160 vehicles. Ford's stated reason names one code and only one: the vehicles "have an On-Board Diagnostics (OBD) system that may falsely set the catalytic converter Diagnostic Trouble Code (DTC) P0430 – Catalyst System Efficiency Below Threshold, causing the Malfunction Indicator Light (MIL) to illuminate even though a repair may be unnecessary." The remedy is a free PCM software update.

Ford's TSB 24-2184 of 6 June 2024 does the same job with no recall attached. On 2018-2020 F-150 trucks with the 2.7L EcoBoost, an illuminated light with "DTC P0420 and/or P0430 stored in the PCM ... may be due to calibration and controls sensitivity," and the published correction is to "perform the catalyst stabilization drive cycle." Not a converter. Not a sensor. A drive cycle.

The cheap cause that gets skipped. Asking whether a calibration exists at all. Half of everything manufacturers publish about this family of codes is software: across the 342 manufacturer documents mentioning P0420 or P0430 that we read for the oxygen sensor guide, 175 (51.2%) involve software, reprogramming or a flash, and none of the 342 summaries instructs replacing an oxygen sensor. The index puts P0430's own share at 48 of 82 bulletins.

Fix it yourself — get the numbers before anyone gets your money. Many inexpensive readers show "Mode 6" test results: the computer's own catalyst score against its limit, per bank. Write down the bank 2 value and its limit. Then, at a steady 2,500 rpm on a warm engine, a live graph should show that bank's front sensor switching quickly while the rear sensor stays far calmer; a rear trace that copies the front one is exactly what the computer is complaining about. Compare bank 2's pair against bank 1's — a two-bank engine hands you a built-in control group. The honest limit: a reader cannot install a manufacturer calibration or run a commanded fuel test.

Where this does not apply. If bank 2's rear sensor is genuinely mirroring the front one and the car rattles or misfires, the sensor is reporting a real problem: Routes 2 or 5.

At the shop — say this: "Before any parts, check for a calibration, TSB or emission recall for P0430 on this VIN. Then show me the Mode 6 catalyst result against its limit for both banks, and a graph of all four oxygen sensors."

Route 4 · Your VIN is on a bank 2 document — recalls, programs and extensions

The tell. Your car appears in the table above, or a letter arrived that you never opened.

What it actually is: the Ford converter programs. Customer Satisfaction Program 19M01, issued 13 June 2019 and extended by Supplement #1 on 23 July 2020, covers 2013-2019 Police Interceptor Utility vehicles with the 3.7L engine built at Chicago. Its terms are unusually generous: the program "extends the warranty coverage of the catalytic converters to 11 years of service or 120,000 miles from the warranty start date of the vehicle, whichever occurs first," it "may be used multiple times as long as the vehicle is within time and mileage limits," and "coverage is automatically transferred to subsequent owners." The stated cause is that "aggressive law enforcement driving maneuvers can result in an overheated catalytic converter, catalyst degradation, and an illuminated malfunction indicator light (MIL) with diagnostic trouble codes (DTCs) P0420 and/or P0430." Program 22M06 of January 2023 repeats those terms for 2019 vehicles, and its Supplement #1 publishes the labor allowances: 2.2 hours rear, 1.7 front, 3.1 both. Program 20M01 of April 2020 extends the same logic to 2013-2019 Lincoln MKT, MKZ and Police Interceptor Sedan models.

The cheap cause that gets skipped. Asking for the campaign by number. One owner in our set wrote that two Ford dealerships "simply cleared the error code (P0430) and made no mention of Campaign 22M06," and that only naming the campaign got the vehicle inspected for a free converter — after they had already bought spark plugs, a purge valve, oxygen sensors and a mass airflow sensor chasing it.

The other lists. Honda's owner notification letter of 29 March 2021 names "P0420 (rear bank ...)" and "P0430 (front bank ...)" alongside the misfire and air-fuel codes, and extends fuel injector coverage to 10 years from the original date of purchase or 150,000 miles, transferring to later owners. Honda also announced an extension on 21 June 2018 for 2006-07 Accord Hybrid cars where "the ECM may misinterpret sensor inputs as deterioration of the warm-up catalytic converter." And in a document dated 14 January 2026, American Honda told dealers it "is searching for certain 2025 Pilots" with P0420 or P0430 stored, asking them to collect parts — the earliest stage of a new problem being recognized.

Where this does not apply. Being the right model and year is not eligibility. Every one of these programs is defined by assembly plant and build date, and 20 of our 106 complainants report being told their car fell outside one.

At the shop — say this: "Run this VIN for every recall, emission recall, customer satisfaction program, special coverage and warranty extension — open or completed. P0430 is still stored; do not clear it before you have checked."

Which P0430 repairs do manufacturers pay for, and which are yours? The answer is written into documents, not left to a service adviser's mood. A 2018-2021 Expedition 3.5L built in the 24E13 window gets a free PCM reprogram because Ford says the code may be false. A 2013-2019 Police Interceptor Utility 3.7L gets converters for eleven years or 120,000 miles under 19M01 and 22M06, transferring to whoever owns it now. A 2016-2019 Honda V6 in the extension window gets injectors for ten years or 150,000 miles. And every light-duty vehicle carries the federal emissions warranty on the converter for 8 years or 80,000 miles. Against that, a leak caused by a reused flange bolt, a misfire from worn plugs, and a converter poisoned by an engine burning oil are yours. Pulscar's free check gives a first read on the idle before that conversation starts.

Route 5 · The bank 2 converter really has failed — rattle, power and the clock

The tell. A loose rattle inside one converter shell at idle or when the cold shell is tapped. Power that fades at speed or uphill, heat through the floor, a strong rotten-egg smell. And a bank 2 monitor result that stays failed after Routes 1 to 4 are ruled out.

What it actually is. The honeycomb inside that bank's converter has melted, cracked or been coated. Because only one bank is affected the car often still drives acceptably, which is why owners let it run — and why the underlying cause gets months to work on the other side too. Several complaints in our set describe exactly that: a P0430 in the spring, a converter, then a P0420 months later, then a quote for both.

The cheap cause that gets skipped. The warranty clock — and on this code more than most, because P0430 arrives earlier. Federal law requires that for light-duty vehicles from model year 1995 the warranty on a "specified major emission control component" runs 8 years or 80,000 miles, and defines that term as "only a catalytic converter, an electronic emissions control unit, and an onboard emissions diagnostic device." California's 13 CCR 2037 adds 7 years or 70,000 miles on high-priced parts. The clock starts at the in-service date, not the model year. In our data, more than half of the P0430 owners who stated a mileage were at or under 80,000 miles when the code appeared: check the date before you accept a bill.

Where this does not apply. A tinny buzz from the outside of a shell is a heat shield, not substrate — and it can sit on top of a real rattle, so tap both. And a converter destroyed by a misfire or burning oil will fail again unless Route 2 comes first; manufacturers do decline coverage for damage from an unrepaired cause. The converter cost guide explains the difference between an inefficient converter and a blocked one.

At the shop — say this: "Give me the in-service date and today's odometer against the 8-year, 80,000-mile federal emissions warranty before you quote. If it is outside, quote bank 2 alone, direct-fit and OEM side by side, and write down what caused the failure."

What does it actually cost to fix P0430 in 2026? It is two price lists with one diagnosis between them. On the short list: a code read at $0 to $40, a diagnostic fee of $80 to $150 at an independent shop or $120 to $200 at a dealer, an exhaust leak repair at $100 to $400, a downstream oxygen sensor at $200 to $400 installed, a misfire repair at $150 to $400, and a drive cycle or a recall reprogram that costs nothing at all. On the long list: a V6 injector set at $1,000 to $2,100 when nobody covers it, a direct-fit converter at $700 to $1,600, an OEM converter at $1,500 to $4,500. The same parts cost $0 inside 24E13, 19M01, 22M06, 20M01, Honda's injector extension or the federal emissions warranty. Pulscar's free check adds a cost estimate for what it hears; the documents decide which list you are on.

P0430 with P0420: what both banks together actually mean

Twenty-four of our 106 P0430 complaints also name P0420 — 22.6% — and the same 24 appear from the other direction in our P0420 analysis, which is a useful sign that both sets were built correctly.

Two converters failing in the same week is not impossible, but it is not where the odds sit. The things both banks share are a much shorter list, and every item on it is cheaper than two converters.

The fuel supply. One failing pump, one bad tank, one pressure regulator, and both banks run wrong at once. An Odyssey owner in our set describes a high-pressure pump failure that, in their words, melted both converters; an Acura TLX owner was quoted $1,540 for a low-pressure pump and $2,461 for the converter it destroyed, in the same visit.

The engine control software. Ford's 24E04 and 24E13 both describe a diagnostic system setting catalyst codes when nothing is wrong, and 24-2184 names "P0420 and/or P0430" in the same breath. A calibration does not know which bank it is wrong about.

The engine oil, and the air going in. Oil reaching the combustion chambers coats both catalysts at the same rate, and debris past a badly seated air filter reaches both banks — GM has a bulletin on exactly that for its V8s, tying it to P0420 and P0430 together.

What to do with the pair. Treat it as a strong hint rather than proof, print the freeze frame for both, and ask the shop what single mechanism would fail two independent converters at once before they quote two. In our set, the owners who paid twice are almost all people who replaced hardware on both sides and found the fuelling problem afterwards.

What 106 federal complaints naming P0430 show

Our sample: every vehicle complaint added to NHTSA's public files between 1 January 2015 and 8 September 2026, de-duplicated by report number — 777,040 unique owner reports. We matched the code in the owner's own description, whole-word and case-insensitive, which matters because these narratives are stored in capitals through about 2020 and in mixed case afterwards.

106 complaints name P0430. One more matched a loose text search and was discarded on reading: a 2012 Ford narrative reading "TER READING SAYS IT IS A P04300 - BAD INNER COOLER." We read all 106 end to end rather than sampling, and gave each a single primary outcome.

Read the limitation before the finding. People file federal complaints about expensive, unresolved or frightening problems. A P0430 fixed free under an extension on a Tuesday essentially never produces one. So this is not a measure of how often each cause occurs. It is a map of what the expensive, unresolved P0430 stories are made of — which is exactly the situation you are in if you are reading a page like this one.

With that said, the map is lopsided in a way the usual advice is not. The largest group by a wide margin is neither the converter nor a sensor: it is the engine feeding that bank, and only one complaint in 106 ends with an oxygen sensor as the named suspect.

Nobody in this file was stranded. Across all 106 reports the crash, fire and towed flags are set in zero, against baselines of 4.37%, 1.82% and 5.11% across the full 777,040-complaint file. About five tows would be the expectation in 106 draws, so a zero is informative without being extraordinary. Read it as this code does not usually strand people — not as permission to ignore a flashing light, which is a different signal entirely.

The mileage gap: why bank 2 shows up earlier than bank 1

This is the finding that surprised us, and the one with the most money attached. We measured the odometer readings in both code sets under an identical rule — keep any figure between 100 and 400,000 miles — so the two are directly comparable.

More than half of the bank 2 complainants were still under the federal mileage limit. Fewer than a quarter of the bank 1 complainants were. For an individual reader that flips the default assumption: with P0420 the odds are that the warranty conversation is already over, and with P0430 the odds are that it has not started.

Now the honest limits, because they matter more than the gap. These are not the same cars measured twice. The P0430 set is dominated by 2016-2019 Honda V6 models whose documented problem is fuel injectors, which fail on a schedule that has nothing to do with catalysts; the P0420 set is dominated by an older Kia Soul converter recall. The gap may be a fact about those two populations rather than about banks. Thirty-one is a small number, only 29% of P0430 complainants state a mileage at all, and mileage is whatever the owner typed. And the warranty is 8 years or 80,000 miles, whichever comes first, so being under the mileage does not by itself put a car inside it.

What the data does support, narrowly and usefully: in this file, the bank 2 code arrives at a lower odometer reading than the bank 1 code, and the majority of the owners who reported it were under the federal mileage limit when it did. If you are looking at a P0430 quote, look at your in-service date before you look at the price.

Who the 106 are: makes, models and model years

One model dominates. The Honda Pilot accounts for 42 of the 106 — 39.6% of every P0430 complaint in a decade of federal records. The Ford F-150 follows with 12, the Honda Odyssey with 6, the Ford Explorer with 4, and the Dodge Durango, Acura MDX and Lincoln MKX with 3 each. By make: Honda 49, Ford 19, Jeep 6, Dodge 5, then Nissan, Chevrolet, Lincoln and Acura with 4 each.

The Honda concentration is tighter than it looks. Of those 49, 48 are 2016-2020 Pilot, Odyssey or Ridgeline — the model range of Honda's own bulletin family for this code, plus two 2020 Pilots one year outside it. That is not a reliability verdict. It is what happens when a manufacturer publishes a warranty extension listing a code by number: owners learn the number, and some type it into a federal form.

By model year, 2016 through 2019 account for 71 of the 106 — 15, 15, 15 and 26 reports. The 2019 peak is the last year of the injector extension window, and the 2019 Pilot alone contributes 15.

By the year the report arrived, the file is front-loaded toward right now: 27 in 2025 and 25 in 2026 to 8 September. Fifty-two of the 106 arrived in the last twenty-one months of the window. Do not read that as converters failing more often; read it as a complaint file that has grown every year plus a coverage argument that teaches people a five-character string.

These are raw counts from makes selling wildly different volumes, and nothing here can normalize them. They are not a reliability ranking.

Twenty owners who were told their VIN was not on the list

Of the 106, 32 report being refused coverage, goodwill or a campaign repair — 30.2%. And inside that group sits a sharper number: 20 of the 106 say they were told their VIN, model year or trim fell outside a named program that described their symptoms and their repair exactly.

That is the characteristic P0430 argument, and it barely mentions the converter.

The shapes repeat. A 2019 Pilot owner at 64,240 miles with no symptom beyond the light, told the VIN range did not include them. A 2020 Pilot owner whose dealer ran the air-fuel test, found cylinders 2, 5 and 6 rich, then explained that the bulletins stop at 2019. A Lincoln MKZ owner holding a Ford document naming their own build plant and dates, told the VIN is not in the range.

The honest limits, and they are not small. These are one side of a conversation, written down by the person who lost it, with no reply on the record. We have not verified any individual refusal and cannot tell a correct application of a coverage rule from a wrong one — a build-date cutoff that looks arbitrary from the driveway is often a real engineering boundary. And 20 is a small number.

What the set shows is not who was right. It is where the argument happens: at a date, an odometer, an assembly plant and a VIN list — all things you can establish before you walk in, and all things a service adviser reads off a VIN in ninety seconds.

At the shop — say this: "Before you quote, read me the in-service date, today's odometer, the engine code on the build sheet, and every campaign this VIN shows as open or closed. If something is declined, write the program number and the reason on the estimate." A refusal with a number on it can be escalated. A refusal without one cannot.

Why your recall lookup can say "no open recalls" anyway

Searching NHTSA's Part 573 safety-recall file for P0430 in the defect, consequence, remedy and notes fields returns nothing, and no investigation resume names it either. Every document on this page is a manufacturer communication or an emission recall.

That is a practical warning rather than a technicality. A lookup that covers safety recalls can honestly return "no open recalls" on a 2019 Expedition that sits inside a 319,160-vehicle emission recall for this exact code, or on a Police Interceptor Utility carrying an eleven-year converter program. Customer satisfaction programs, special coverages and warranty extensions are dealer-system documents; they answer to a VIN and a program number, and nothing else will surface them.

So the second call is not optional. Ask a franchise dealer, in these words, for every campaign on this VIN, open or closed, including customer satisfaction programs and warranty extensions — and if you already know a number that fits your car from the table above, say the number out loud.

P0430 by make: what the file says about the five that dominate searches

People do not search "p0430 code" on its own for long; they add the badge. Here is what our 106 complaints and the documents say about the makes that come up most.

Ford — 19 complaints, and the largest documents. Twelve F-150s, four Explorers, one Expedition, two Tauruses. Ford is the only manufacturer here with a federal emission recall whose stated defect is that the car sets this code when nothing is wrong, and it has two: 24E13 and 24E04. Add 24-2184's drive cycle and the 3.7L converter programs, and the rule writes itself: on a Ford, exhaust the paperwork before you touch the exhaust. One owner paid $2,975 for converters and was later told they were probably fine.

Honda and Acura — 53 complaints, and one story. Forty-two Pilots, six Odysseys, one Ridgeline, three MDXs, one TLX. The story is fuel injectors, documented across 17-036, 19-072, 19-073, 20-100 and 21-010, with an extension to 10 years or 150,000 miles. The words that matter at the service desk are cylinder air-fuel test and injector warranty extension, in that order. On a 2020 or 2025 Pilot, Honda is still gathering parts and no fix is published.

Chevrolet, GMC and Buick — 7 between them, no cluster. The useful GM documents are the air-filter-seal bulletin tying debris past a badly seated filter to P0420 and P0430 on V8s, and PIP5110C on leaks before converters. Both are cheap-first, and both are easy to ask for by name.

Jeep, Dodge and Chrysler — 12 complaints, the most mixed group. A Grand Cherokee whose dealer flashed the PCM under a bulletin and cleared the light; a Durango whose code returned after a converter because the valve seals were leaking oil; a Wagoneer whose dealer wrote that the number 5 injector was causing the fault. The index counts Stellantis as the largest single publisher of bulletins naming this code, so asking for a bulletin search is the highest-value question on these cars.

Nissan and Infiniti — 6 complaints. Titan, Armada, Pathfinder, QX56, mostly converters replaced or quoted past 110,000 miles with no upstream diagnosis recorded. One Pathfinder's P0430 turned out to be crankcase ventilation failure with oil blow-by and sludge — the slow version of Route 2, and the one that ruins a new converter fastest.

How to pull your own car's federal record in 10 minutes

Everything above came out of files anyone can open. Four steps, in the order that answers the money question fastest.

1. Run the VIN on NHTSA's recall lookup. It returns open, unrepaired recalls, including emission recalls — which is how a 24E13 Expedition finds out. It does not show completed campaigns, and it does not show programs or extensions.

2. Then ask a dealer, using the word "program." "Every campaign on this VIN, open or closed, including customer satisfaction programs and warranty extensions." An owner in our set only got a free converter after naming 22M06 out loud.

3. Read the manufacturer communications for your year, make and model. NHTSA republishes every one it receives; the field layout describes the columns and the PDFs sit under static.nhtsa.gov with the numbers used in Sources below. Our Check Engine Code Index does this across the seventeen most common codes.

4. Check the in-service date against the clock, and note the odometer. The date the car was first sold — not built, not the model year — starts the federal 8-year, 80,000-mile emissions warranty and most manufacturer coverages. On this code that date is more often decisive than on any other in our index.

Clearing P0430 before an inspection: why it comes back

Clearing the code on the morning of the test fails for three documented reasons, and on this code it can be expensive as well as futile.

The light is an automatic fail. Under 40 CFR 85.2222, the federal procedure for OBD inspections, a vehicle whose check engine light is commanded on "shall fail the OBD inspection."

A freshly cleared car is not ready. The same rule allows 2001 and newer vehicles no more than one unset readiness monitor. Clearing resets the monitors, and the catalyst monitor only runs again under specific driving conditions — exactly what Ford's catalyst stabilization drive cycle is for. Arrive too soon and you are turned away as not ready; arrive later and the code is back.

Clearing can close a free repair. Several of the programs on this page only open when the code is actually stored, and the owner whose dealerships "simply cleared the error code" twice without mentioning 22M06 spent a year buying parts before anyone ran the program.

The honest route to a pass is the repair, then the drive cycle, then a readiness check with your own reader before you queue.

What actually happens at the shop, checkpoint by checkpoint

Checkpoint 1 — the VIN question. "What recalls, emission recalls, customer satisfaction programs and extensions show on this VIN, open or completed?" Free, and on Route 4 cars it decides everything.

Checkpoint 2 — the full code list, both banks. "Which codes are stored, pending and in history, is P0420 among them, and what does the freeze frame say?" A P219B or a misfire in history changes the entire job.

Checkpoint 3 — the leak check on that bank. "Was the exhaust on bank 2 checked for leaks between the manifold and the rear oxygen sensor, and how?" GM puts this before any converter, in writing.

Checkpoint 4 — the data and the calibration. "What is the Mode 6 catalyst result against its limit for bank 2 and for bank 1, and is there a calibration or drive-cycle bulletin for this code on this engine?" Comparing the two banks is free.

Checkpoint 5 — the fee, the clock and the ceiling. "What is the diagnostic charge, is the converter inside the 8-year, 80,000-mile emissions warranty, and will you call me before anything over this figure?" The overcharging guide covers how quotes inflate.

Three diagnostic traps that cost owners the most

Trap 1: two converters quoted from two codes. The situation: P0430 and P0420 arrive together on a V6 at 90,000 miles, engine smooth. What the shop says: "Both cats are done. Two converters, plus labor." What is really happening: two independent converters rarely fail in the same week, and Ford has recalled 319,160 Expeditions and 90,892 F-150 hybrids for setting these codes falsely. Price versus bill: $0 for a reprogram or a drive cycle, against two converters. Your protective question: "What single mechanism would fail both converters at once, and have you checked for a calibration on this VIN?"

Trap 2: the injectors nobody looked for. The situation: a 2017 Pilot at 60,000 miles, P0430, no misfire code on a cheap reader. What the shop says: "Bank 2 cat. About two thousand." What is really happening: Honda's own procedure runs a cylinder air-fuel test first and replaces the injectors that fail it, under an extension to 10 years or 150,000 miles. Forty-eight of our 49 Honda complaints sit inside that model window. Price versus bill: $0 for injectors inside the extension, against a converter a rich-running cylinder will destroy again. Your protective question: "Has a cylinder air-fuel test been run on bank 2, and does this VIN have the injector warranty extension?"

Trap 3: the code cleared before the program was checked. The situation: a Police Interceptor Utility or an Expedition, P0430, and a quick-lube offering to reset the light. What the shop says: "It's probably nothing. We'll clear it and see if it comes back." What is really happening: the programs that pay for this open on a stored code and a VIN, not on a memory of one. An owner in our set watched two dealerships clear it without ever naming 22M06. Price versus bill: $0 for a program converter, against $1,500 to $4,500 plus the parts you buy while guessing. Your protective question: "Can you read and save the codes without clearing them, so the program can be checked against the VIN?"

Three quotes, decoded

These are composite scenarios, not individual customers — the mileages and outcomes are typical of the pattern each describes, assembled so the arithmetic is visible. We do not publish invented testimonials.

Scenario 1 — the Expedition that needed software. A 2019 Expedition at 71,000 miles, P0430 alone, engine smooth. The first quote is a bank 2 converter at $1,900. The owner runs the VIN, finds emission recall 24E13, and the dealer reprograms the PCM at no charge because Ford's own position is that the system may set this code when nothing is wrong. Lesson: on this code the recall list is a diagnostic step, not paperwork.

Scenario 2 — the Pilot that needed injectors. A 2017 Pilot at 63,000 miles with P0430 and P219B. A converter is quoted on the code. The dealer instead performs the software update and the cylinder air-fuel test, two cylinders fail rich, the injectors are replaced under the 10-year extension, and both converters stay on the car. Lesson: on a documented engine, the manufacturer's order of work is the cheapest order.

Scenario 3 — the truck that needed a drive cycle. A 2019 F-150 2.7L at 88,000 miles, intermittent P0420 and P0430 for weeks. No leak, no misfire, normal fuel trims; the shop reads TSB 24-2184, performs the catalyst stabilization drive cycle, and the monitor completes and passes. Total parts: none. Lesson: a documented drive cycle is a repair, and the cheapest one here.

Should you buy a used car that has thrown P0430?

This is the question that sends most people here from a listing rather than a driveway, and the answer is genuinely different from the one for most codes.

Ask which route it was, and get it in writing. A P0430 answered by a recall reprogram, a drive cycle or an injector replacement under an extension is a repaired car with a documented history — often better documented than the identical car that never threw a code. A P0430 answered by a converter, with no explanation of what killed it, is an unfinished repair that will bill the next owner.

Check whether the coverage transfers, because on these cars it usually does. Ford's 19M01 and 22M06 state that "coverage is automatically transferred to subsequent owners." Honda's injector extension covers "the original owner and any subsequent owners." A used 3.7L Police Interceptor Utility inside eleven years of service carries a converter program most sellers have never heard of — a reason to look at one, not away.

The one combination to walk away from is a P0430 with a misfire history, oil consumption and a converter already replaced once. That sequence appears repeatedly in our repeat-failure group, and the next converter is on whoever owns the car when the monitor runs.

What to pay for. A pre-purchase inspection that pulls stored and pending codes, reads Mode 6 on both banks, and hands you a printout. It costs a fraction of one converter and answers the only question that matters: is the cause fixed, or just the symptom?

After the fix: verify, then prevent

Verify the monitor, not just the light. Drive for a week, then check with your own reader that the bank 2 catalyst monitor shows complete and that P0430 has not returned as pending.

Fix the cause and keep the paperwork. The invoice should name what killed that converter and how it was repaired — that document is what a warranty claim, a resale and any future argument all turn on.

Protect the new part. Treat a flashing light as a stop-soon event, fix oil consumption before it becomes a second converter, keep the air filter box sealed, and do not ignore a fuelling complaint because the car still drives. The check engine light guide covers the next light. Thirty seconds of a cold start recorded now turns the next rattle into a comparison instead of an argument; the recording guide has the method.

Sources and documents

Primary documents only. Where a claim is marked 🟢 it rests on an item below, opened and read, with every population, date and quoted phrase taken from the document itself. Claims marked ⚪ are estimates or owner reports.

1. Ford Emission Recall 24E13, dealer letter 16 April 2025 — 2018-2021 Expedition 3.5L EcoBoost, Kentucky Truck, built 14 March 2017 to 27 December 2021; US population 319,160; OBD system "may falsely set" DTC P0430; free PCM reprogram; California and Massachusetts Proof of Correction. Dealer letter (PDF) · Owner letter (PDF)
2. Ford Program 19M01, 13 June 2019, and Supplement #1, 23 July 2020 — 2013-2019 Police Interceptor Utility 3.7L, Chicago; converter coverage to 11 years or 120,000 miles, transferable, usable more than once. 19M01 (PDF) · Supplement #1 (PDF)
3. Ford Program 22M06, 26 January 2023, and Supplement #1 — 2019 Police Interceptor Utility 3.7L built 18 May 2018 to 26 February 2019; same terms; labor 2.2 h rear, 1.7 h front, 3.1 h both. 22M06 (PDF) · Supplement #1 (PDF)
4. Ford Program 20M01, 2 April 2020 — 2013-2019 Lincoln MKT, MKZ and Police Interceptor Sedan; overheated converter, MIL with P0420 and/or P0430. Program (PDF)
5. Ford TSB 24-2184, 6 June 2024, superseding 24-2115 — 2018-2020 F-150 2.7L EcoBoost; "calibration and controls sensitivity"; remedy is the catalyst stabilization drive cycle. Bulletin (PDF)
6. Ford Emission Recall 24E04, 5 November 2024 — 90,892 2022-2023 F-150 hybrids; OBD system "may falsely set" P0420 and/or P0430. Bulletin and letter (PDF)
7. Honda SB 17-036, 31 July 2017 — 2016 Pilot; "The MIL comes on with DTC P0430 (front bank catalyst system efficiency below threshold [Bank 2]). The PCM software may misinterpret sensor inputs as a deteriorated catalytic converter." Bulletin (PDF)
8. Honda SB 19-072 and 19-073, version 4 of 11 February 2021 — "MIL Comes On with DTC P0430 or P0430 with P030X, P219A, P219B," with and without a software update; both replaced by 20-100. 19-072 (PDF) · 19-073 (PDF)
9. Honda Owner Notification Letter, 29 March 2021 (bulletin 21-010) — 2017-19 Pilot and Ridgeline, 2018-19 Odyssey; names P0420 as rear bank [bank 1] and P0430 as front bank [bank 2]; injector warranty extended to 10 years or 150,000 miles, original and subsequent owners. Letter (PDF)
10. Honda SB 20-100, 24 November 2020 — 2016 Pilot, software plus injectors, same extension. Bulletin (PDF)
11. Honda dealer message ATI&01142026905, 14 January 2026 — American Honda "is searching for certain 2025 Pilots" with P0420 and/or P0430 stored. Message (PDF)
12. GM PIP5110C, July 2015 — "This repair must be attempted before considering the replacement of a catalytic convertor." PIP (PDF)
13. GM 16-NA-111, March 2019 — air filter seal, debris past the filter, P0420 and P0430 on V8s. Bulletin (PDF)
14. Subaru SIB 09-110-23R, revised 7 November 2023 — the diagnostic order, leak inspection ahead of any exhaust part. Bulletin (PDF)
15. 42 U.S.C. 7541(i)(2) — the federal 8-year, 80,000-mile converter warranty. Statute
16. 13 CCR 2037 — California, 7 years or 70,000 miles for high-priced parts. Regulation
17. 40 CFR 85.2222 — OBD inspection and readiness rules. Regulation
18. Our P0430 complaint analysis — all 106 complaints read in full and classified; 20 campaign-exclusion reports and 32 refusals counted; mileage compared with P0420 under an identical rule. Method · all 106 classified (CSV) · by make and model (CSV) · model year and report year (CSV) · warranty clock (CSV) · CC BY 4.0
19. Our 342-bulletin analysis of P0420 and P0430 — February 2015 to August 2026: 175 involve software, 88 name an engine cause, 26 mention an oxygen sensor, 0 prescribe one. Bulletin CSV · method
20. Our 100-complaint read of P0420 and P0430 — drawn at random from the 376 naming either code: 36 an upstream engine fault, 18 the converter, 8 software or a campaign, 5 an oxygen sensor. Classified CSV
21. Pulscar Check Engine Code Index — 82 bulletins naming P0430 across 8 manufacturer groups, at least 48 software updates, 4 campaign-linked. Index · code index (CSV)
22. Our complaint sample — 777,040 unique complaints added 1 January 2015 to 8 September 2026. NHTSA complaint file layout

What we looked for and did not find. No safety recall in NHTSA's Part 573 file names P0430 in its defect, consequence, remedy or notes text, and no investigation resume names it. We could not find a published rule fixing which physical side of an engine is bank 2 across manufacturers, because there is not one — Honda says front, Ford's labor tables do not say. And we could not re-price this repair in this pass: the estimator sites that publish these ranges refuse automated access, and we do not work around that.

Codes and lights: check engine light, P0420, P0300 misfires, P0171, P0128, P0442, P0455, flashing light, most expensive codes. Parts: catalytic converter cost, oxygen sensor cost, fuel injector cost. Symptoms: rattling, power loss uphill, hesitation. Cars and money: Honda Pilot, Ford F-150, warranty extensions, diagnostic costs, our story.

Methodology. Populations, build windows, program terms, labor allowances and quoted phrases come from the documents above, downloaded from static.nhtsa.gov and read as text on 19 September 2026. Complaint counts come from NHTSA's public complaint files, de-duplicated by report number; they are owner reports, not audited repairs, and not failure rates. Price ranges are estimates carried forward from the September 2026 review of our cost guides. Eligibility for every program named here depends on your VIN.

Prices verified September 2026 and reviewed quarterly — no estimator site would serve our checks in this pass, so the dollar ranges are carried forward unchanged and remain marked as estimates. Technical documents verified September 2026: every Ford and Honda document quoted above was downloaded and read on 19 September 2026.

Had P0430 diagnosed, or paid for a bank 2 converter that did not fix it? Email [email protected] with the year, engine, mileage and what finally cleared the code — owner data is how these ranges get sharper.