PULSCAR ANALYSIS - P0316 (MISFIRE DETECTED ON STARTUP, FIRST 1,000 REVOLUTIONS) AND MISFIRE OR ROUGH RUNNING AT START-UP IN NHTSA'S PUBLIC FILES PulsCar analysis of NHTSA public data, October 2026. License: CC BY 4.0 Attribution: "PulsCar analysis of NHTSA public data, October 2026." Published alongside https://www.pulscar.io/blog/p0316-code ------------------------------------------------------------------------------ Prepared October 2026. Source data: NHTSA public flat files (complaints received 1 January 2015 to 4 October 2026 - the latest received date in the files; the index of manufacturer communications) and documents downloaded one at a time from static.nhtsa.gov. The NHTSA complaint file is public: anyone can download it from NHTSA and check any number here against it. 1. Complaints (1,801) Scope: the code P0316 ("misfire detected on startup, first 1,000 revolutions") and a misfire or rough running at start-up or on a cold start described in the owner's words; the other misfire codes P0300-P0308 only where the complaint ties them to starting. First search (906): every complaint whose narrative (a) names the code P0316 by any spelling we searched (a letter O for zero, a space, hyphen or period after the P, the suffix 00, or a bare number after "code", "DTC", "error", "CEL" or "fault"), (b) uses the code's own wording ("first 1,000 revolutions", "misfire detected on start-up"), (c) says misfire (or miss-fire, missfire) together with a start-up word (start-up, cold start, first start, when, after, upon, on, at or during starting, cranking, cold engine, cold morning, in the morning, every morning) in the same sentence, or (d) describes rough running (rough idle, runs rough, stumble, stutter, sputter, the engine shaking, vibrating, shuddering, jerking or hesitating) together with a strict start-up word in the same sentence. Nothing was sampled: every narrative the searches returned was sorted. The exact search wording is in codebook.txt. Left out on purpose: narratives that describe a misfire or rough running only while driving, at speed, under load or "all the time", with no start-up wording and without the code P0316; the other misfire codes (P0300-P0308) have their own pages. Other misfire codes are counted here only where the complaint ties the misfire to starting. Independent check (895): a separate search of the whole complaint file for what the first one missed, run after the first batch was sorted. About 2,900 narratives were read against the same relevance rule; 895 were added (start-up written in other words: "while starting", "when the vehicle was started", "as soon as I start it", "the first few seconds", "until it warms up", "after sitting overnight", "when cold", "rough start"; the NHTSA contact-style wording "the contact stated while starting the vehicle, the engine was misfiring" is the largest block; the code written p316, 0316 or "code 304 and 316"; a misfire word in one sentence with the start-up cue in the next). The check stopped at its row cap of 900 with 895 added, so some start-up misfire complaints with unusual wording are certainly still not in the set. Of the 895, the sorting counted 853 as relevant. found_by in the complaints file says which search found each complaint ("first search" or "independent check"). Sorting: the sorting rules (codebook.txt) were written, dated and fingerprinted before any complaint was sorted; an addendum for the second batch was fingerprinted before that batch was sorted. Every complaint was sorted twice, independently, by the same written rules, each time from the rules alone, without sight of the other sorting (columns sorting_1_ and sorting_2_). One category (C ignition coil; P spark plugs; I injector or fuel; M engine mechanical; A air, sensor or wiring; F software or campaign only; O another cause; K checked and cleared by a shop; U no diagnosis or repair stated; N not a start-up misfire of the kind studied) and five flags (startonly: the rough running happens only or mainly at start-up and clears or is much better once the engine runs or warms; stall; flash: a flashing check engine light; recall: a recall, bulletin, special coverage or "known issue" notice is mentioned for this fault; returned: the same fault came back after a repair or the repair did not fix it). Each sorting saw an excerpt around the matching words (about 300 characters either side), or the whole narrative when nothing matched. Agreement of the two first sortings (before any settling or check) over all 1,801: category 92.6% (1,667 of 1,801); startonly 96.1%; stall 95.6%; flash 99.3%; recall 96.8%; returned 97.2%. Settling: every complaint on which the two sortings differed in any of the six fields (342 complaints) was settled by one of the written rules listed in codebook.txt; the rule applied is in the rule_applied column. A first consistency check then re-read the 170 complaints that had been sorted to a coil, plug, injector, air/sensor/wiring or engine-mechanical cause together with "the problem came back" and applied the rule that a part which did not cure the problem does not count as the cause: 33 of those changed category, nearly all to "no diagnosis or repair stated" (Rcons1 in codebook.txt). A final check re-read on the full text the complaints that had been sorted from short excerpts: all those sorted to a cause other than engine mechanical, plus all those with no cause stated (856 in all). 135 were changed under the same written rules (104 to engine mechanical, 13 to injector or fuel, 12 to checked and cleared, 4 to another cause, 2 to air, sensor or wiring; Rcons2 and Rcons3 in codebook.txt). The resolution column says "changed in consistency pass" for every complaint either check changed. Result: 1,602 relevant (749 from the first search, 853 from the independent check), 199 not relevant. Counts are counts of complaints, not cars. A complaint is evidence that an owner wrote to NHTSA; nothing here is a failure rate. 2. Documents NHTSA's index of manufacturer communications lists 441 bulletins whose summary names P0316 or the words "first 1,000 revolutions" (76 do) or ties a misfire or rough running to start-up or a cold start. Not all of them could be read. Chosen: 224 whose summary names P0316 or says the misfire or rough running happens at start-up or on a cold start (tier A), and 108 more whose summary ties a misfire or rough idle to cold weather, carbon, injectors, spark plugs, coils, fuel pressure or a software update with start-up implied (tier B), each chosen by reading the index summary. 29 Toyota and Lexus bulletins about rough idle from the EGR system that never say misfire were then set aside, leaving 303. Index entries judged to mention misfire or rough running only in passing, only under load or when warm, only the codes P0300-P0308 with no start-up link, or hard start without uneven running (106), and papers about heavy trucks, buses, motorcycles or unrelated faults (3), were not chosen. Index entries not chosen are not evidence of anything. The independent check added 135 more bulletins (hard start or long crank with rough running, rough idle or misfire on a cold start or during warm-up, and cold-start software notices, found without the usual codes). Files: 438 index entries were requested (303 from the first list, then 135 from the independent check); 435 of them have a file, 438 files in all (some bulletins have two or three files; 373 distinct documents once the 65 exact copies are set aside). The NHTSA index gave no downloadable file for these ids: 10057004, 10093692, 10162441. They are listed in documents.csv with "no file on NHTSA" in the read column and nowhere else. Reading: the files fall into groups of near-identical documents (revisions, copies, look-alikes). One representative of each group was read in full; the other files of the group were compared with their representative line by line (243 read in full, 195 compared; 65 of the files are exact copies, with the same text as another file, and the rest differ only in details such as a revision date, a model list or a part number, which the comparison recorded). 25 files whose PDF had no readable text were read from images of their pages. Every verbatim quotation was checked against the text of the named document, with the page number. The document list says, for each file, whether it was read in full or compared, whether its own text names P0316 (70 files do) or another P030x misfire code (242 files do), and its relevance (DIRECT: about this fault, a misfire or rough running at start-up or on a cold start, or P0316; LISTED: the target code is one of many in a list; RELATED: a companion code or the same symptom from another cause; NOT RELEVANT). Vehicle years, engines, build dates and coverage terms are as printed in the documents. Coverage status "as of September 2026" is the authors' computation from printed terms. duplicate_of marks exact copies (same text as another file); a second or third file of the same bulletin is listed as the bulletin id followed by -2 or -3. pdf_url is the NHTSA file address on static.nhtsa.gov. Recalls: NHTSA's recalls table (campaigns from 2010 to October 2026) was searched for the word misfire in the defect and consequence text. Of the campaigns that name misfire, none describes a start-up misfire; the few the article quotes are about another fault (for example a catalytic converter that overheats after a misfire, or a loose coil ground bolt), and their words are quoted from the table. 3. Owner-reported amounts (296 figures in 238 complaints) One written inclusion rule (fixed before the figures were decided): a dollar figure is included when the owner states it as a price, charge, bill, quote, estimate or part price for diagnosing or repairing a start-up misfire or rough start on that vehicle: ignition (coils, spark plugs, tune-up), fuel (injectors, carbon or intake-valve cleaning, fuel pump or pressure), engine work tied to the misfire (cylinder head, head gasket, coolant leak into a cylinder, short block, long block, engine replacement, valves, cam phasers), sensors, wiring or software tied to the misfire, or a diagnostic fee. Excluded: mileage written as "NNk"; vehicle price, value, payments, trade-in, buyback, refund or reimbursement demands, settlement and lemon-law sums; repairs of other systems unless the owner ties them to the misfire; towing and rental-car costs; totals that mix the misfire repair with unrelated work unless the owner attributes the figure to the misfire repair; restatements of a figure already counted in the same narrative; other owners' costs; figures not tied to the start-up misfire. Status comes from the owner's own words (paid, billed, quoted, not stated); group is ignition, fuel, engine, mixed (several of these in one price), other (sensor, wiring, software, other part) or diag (diagnostic fee). 390 candidate figures were found in the 272 relevant complaints that contain a dollar figure and 94 were excluded, each with its reason (p0316-excluded-figures.csv). Figures are what owners wrote, not audited invoices. 4. Limits The complaint file holds the cases where an owner wrote to NHTSA, in the owner's words, with no verification; owners whose trouble ended are mostly not in it. The shares reported describe the complaints, not all cars, and no rate of failure can be computed from them. Only 157 relevant narratives print P0316 themselves (144 Ford, 11 Lincoln, 1 Land Rover, 1 Volkswagen); the rest describe the event in words, which is why the set is built on wording as well as on codes. The independent check stopped at its row cap (900) with 895 added, so some start-up misfire complaints with unusual wording are certainly still not in the set. Complaints that describe a misfire only while driving or under load were left out by rule, and some of them may be the same fault in plainer words. The two sortings first saw only an excerpt around the matching words; the final check used the full narratives, but it did not re-read the 746 complaints that were already sorted to engine mechanical, so a later cause named after an excerpt ends could still be missed there. Category agreement between the two first sortings (92.6%) is lower than for the yes/no questions; that is why every disagreement was settled by a written rule and why the article reports the share of complaints where no cause was stated. The document set holds what NHTSA's index lists and what could be read; a maker paper that is not in the index is not in it, and 3 chosen index entries have no file to read. The recalls table and the investigation summaries were not part of this set.