PULSCAR ANALYSIS — P0174 (SYSTEM TOO LEAN, BANK 2) IN NHTSA'S PUBLIC FILES PulsCar analysis of NHTSA public data, September 2026. License: CC BY 4.0. Attribution: "PulsCar analysis of NHTSA public data, September 2026." Published alongside https://www.pulscar.io/blog/p0174-code ------------------------------------------------------------------------------ 0. WHAT THIS FILE ADDS, AND WHAT IT DOES NOT REPEAT ------------------------------------------------------------------------------ The Check Engine Code Index already counts manufacturer bulletins naming P0174 (48 bulletins from 6 groups, software in at least 19, 12 of 39 outside Stellantis) by its own method. Cited, not recomputed: https://www.pulscar.io/blog/check-engine-code-index This file does something different: it collapses every manufacturer communication record naming P0174 into distinct documents and reads each. The P0171 guide covers bank 1 and the complaint file for it: https://www.pulscar.io/blog/p0171-code ------------------------------------------------------------------------------ 1. SOURCE FILES ------------------------------------------------------------------------------ NHTSA's published flat files, downloaded 24 September 2026 and loaded into SQLite without modification: COMPLAINTS_RECEIVED_2015-2019, _2020-2024, _2025-2026: 780,071 distinct vehicle complaints by ODI number, received 1 Jan 2015 - 21 Sep 2026 FLAT_RCL_POST_2010 (recalls reported from 2010) TSBS_RECEIVED_2015-2019, _2020-2024, _2025-2026 (manufacturer communications) FLAT_INV (investigations) Primary documents downloaded from static.nhtsa.gov and read in full on 24 September 2026 (15 of the 38 grouped documents): Nissan NTB20-009A (NHTSA 10199168), Infiniti ITB20-005 (10172179), Nissan NTB19-022 (10158432), Nissan NTB19-030 (10160183) and Infiniti ITB19-010 (10160178), GM 21-NA-105 (10194116), GM 22-NA-171 (10231421), GM PIP5686A (10168955), GM N192273400 (10169635), Toyota T-SB-0166-19 Rev1 (10171454), Toyota T-SB-0009-23 (10235216), Ford SSM 48573 (10171964) and SSM 49050 (10179316), Ford TSB 20-2324 (10180534), Stellantis 14-005-21 (10221675) and 09-025-25 (11022171), American Honda dealer message of 10 May 2022 (10213569). All other documents: NHTSA's published summary text. Two first-pass classifications from summaries were wrong and corrected after reading in full: NTB19-030/ITB19-010 are engine computer reprograms, not sensor replacements; the Acura message is a fuel injector study in which lean codes are optional. ------------------------------------------------------------------------------ 2. THE COMPLAINT SET (p0174-25-complaints-read.csv) ------------------------------------------------------------------------------ Case-insensitive match on 'p0174', 'p 0174' and 'po174' in the narrative: 26 complaints. One (ODI 11699237) writes "P01741" in a transmission complaint and was excluded. 25 remain, every one read in full. Also name P0171: 20 of 25 Toyota: 5 (2008 Tacoma, 2017 Highlander, two 2019 Highlanders, 2020 Avalon) - all five describe fuel pressure, refuelling or a fuel pump GM (Buick, Chevrolet, GMC): 8 Describe a stall or an engine that would not stay running: 9 (8 by pattern; the 2017 Pacifica, which will "shutter and die", by reading) Received 2015-2026. The set is small: P0174 is rarely a safety complaint on its own. Nothing here is a failure rate. ------------------------------------------------------------------------------ 3. THE DOCUMENT SET (p0174-documents.csv) ------------------------------------------------------------------------------ Full-text match 'P0174' on the manufacturer communications summaries: 84 records. Revisions, supersessions, re-filings and the 16 versions of one Acura dealer message were grouped into 38 distinct documents by bulletin number and text. Each was assigned one lane by reading it: software / calibration 15 (7 of them Stellantis) air leaks, PCV, intake 7 fuel supply, fuel quality, flex-fuel learning 6 EVAP and purge 2 A/F sensor and its diagnosis 2 engineering information and parts collection 4 water entry, repair-induced 2 Documents naming P0174 without P0171: 5 (Nissan NTB20-009/009A, Infiniti ITB20-005, Ram 14-005-21, GM PIP5187, Ford SSM 48573). In the first four, P0174 is the only lean code. Warranty terms quoted in the article come from the documents themselves: GM 21-NA-105 (ECM reprogramming 8 years/80,000 miles, U.S.) and Toyota T-SB-0166-19 (Federal Emission Warranty, 96 months or 80,000 miles). ------------------------------------------------------------------------------ 4. RECALLS ------------------------------------------------------------------------------ Recall defect texts do not usually name trouble codes; no recall since 2010 names P0174. Recalls cited in the article (Toyota 20V-012 and 20V-682, Subaru 20V-218) are fuel pump recalls documented in our P0087 and P0171 analyses: https://www.pulscar.io/research/p0087-code/method.txt ------------------------------------------------------------------------------ 5. PRICES ------------------------------------------------------------------------------ Price ranges in the article are US shop estimates carried from PulsCar's P0171, fuel pump and related repair guides, verified July to September 2026. Nothing was re-priced for this analysis: the estimator pages we would use refused automated checks in September 2026. The one owner-reported amount in the P0174 set ($523.80, ODI 11365016) is published with its ODI number. ------------------------------------------------------------------------------ 6. LIMITS ------------------------------------------------------------------------------ Complaints are self-reported and over-represent bad outcomes. Bulletins name conditions a manufacturer saw often enough to write about; absence of a bulletin does not mean absence of a problem. Pattern flags were checked against the matched passages.