PULSCAR ANALYSIS - P0410 (SECONDARY AIR INJECTION SYSTEM) AND ITS CODE FAMILY 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/p0410-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; manufacturer communications; recalls since 2010) and documents downloaded one at a time from static.nhtsa.gov. 1. Complaints (559) First search (508): every complaint whose narrative names P0410 by any spelling we searched (a letter O for zero, a space, hyphen or period after the P, the suffix 00, or a bare 410 after "code", "DTC", "error", "CEL", "coded" or "fault"), or a sister code of the secondary air family (P0411 to P0419, P0491, P0492, P2430 to P2449) in the same spellings, or describes the secondary air system in owners' words (secondary air, air injection, air pump, smog pump, air switching valve, SAI pump or valve) together with a word about a fault, a repair or a symptom. The exact text searches are in codebook.txt. The pool was small enough to sort in full; no sample was drawn. Completeness check (51): an independent search of the same file for what the first one missed, run after the first batch was sorted. It found complaints that use the secondary air words with none of the context words, and other names for the same system ("secondary injection pump", "air intake pump", "air induction pump", "A.I.R. pump", "combi valve" and similar). No complaint was found that names a P0410-family code in a spelling the code searches missed. Every complaint it proposed that meets the unchanged relevance rule was added; found_by in the complaints file says which search found each complaint. 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. One category (N not a secondary-air event on this vehicle; P air pump; V valve; M whole system or several parts; W electrical; L hoses and ports; F software or campaign procedure only; O another cause; K checked and cleared; U nothing found or done stated) and four yes/no flags (power, fire, recall, returned) were recorded for each. The sorting was done on excerpts of about 300 to 400 characters around the matching words (the whole narrative when nothing matched). Agreement over all 559: category 513 (91.8%); power 552 (98.7%); fire 558 (99.8%); recall 547 (97.9%); returned 551 (98.6%). Settling: every disagreement (68 complaints) was read and settled by one of the written rules R1 to R13 (listed in codebook.txt); the rule applied is in the rule_applied column. A consistency check then reviewed the 76 complaints on which both sortings had agreed on "nothing diagnosed" yet the narrative mentions a dealer, shop, price or warranty decision, and changed 43 rows under the same rules (resolution says "changed in consistency pass"; 41 changed the category, 2 only a flag). Result: 483 relevant, 76 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. Some owners filed the same text more than once under different ODI numbers; each filing is one row, and the amounts file counts such a text once. 2. Documents (189 index entries, 178 files read or compared) First search: NHTSA's index of manufacturer communications, entries whose summary names a code of the secondary air family or describes the secondary air system with a word about a fault, a repair or a software update: 131 entries. Completeness check: 58 more entries found by the independent search. 3 entries have no file on NHTSA; 8 heavy-truck and bus papers were set aside. Reading: 88 representative documents were read in full (14 of them image-only scans, read from images of their pages); 90 further files (revisions, copies and look-alikes of those) were compared with the representative line by line. Every verbatim quotation in the article was checked against the text of the named document or complaint. The Subaru recall was read from the dealer campaign bulletin and the owner letter; NHTSA lists no separate Part 573 report file for it. Model years, engines, build dates and coverage terms are as printed in the documents, never taken from NHTSA's index, which expands years. Coverage status "as of September 2026" is the authors' computation from printed terms. duplicate_of marks exact copies (same text as another file): 24 files, leaving 154 distinct documents among the 178 files read or compared. Only two documents (two versions of one Bentley table) print P0410. Maker papers use the family's other codes. 3. Owner-reported amounts (149 figures in 135 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 or quote for diagnosing, repairing or replacing the secondary air system or one of its parts (air pump, switching or combination valve, relay, hoses and ports, pressure sensor, the whole system or module, a bypass kit), or the part price of one of them, on that vehicle. Excluded: mileage written as "NNk"; vehicle prices, values, payments, trade-ins, buybacks and refund demands; other systems; totals that mix secondary air work with other major work unless the owner attributes the figure to the secondary air repair; restatements and the same text filed twice; other owners' costs; quotes in a currency other than US dollars (and a small figure in the same narrative as such a quote, when the currency is unclear); line items already inside a stated total. Status comes from the owner's own words (paid, billed, quoted, offered, not stated); group is system, pump, valve, part, mixed or diag. 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. Toyota and Lexus account for 405 of the 483 relevant complaints; the shares reported describe the complaints, not all cars. The document set holds what NHTSA's index lists; a maker paper that is not in the index is not in it. Motorcycles, buses, heavy trucks, tire air pumps and air suspension compressors are outside the study and are sorted N.