PULSCAR ANALYSIS — P0135 AND OXYGEN-SENSOR HEATER CODES 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/p0135-code

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Prepared 25 September 2026. Source data: NHTSA public flat files (complaints received 2015 to 21 September 2026, 780,071 records; manufacturer communications from January 2015; recalls from 2010) and documents downloaded from static.nhtsa.gov.

1. Heater-code complaints (62, all read in full)
   Case-insensitive search of narratives for heater and heater-adjacent codes P0030-P0038, P0050-P0060, P0134, P0135, P0141, P0155, P0161 (also with a space or hyphen), plus full-text search for (o2 OR oxygen OR a/f OR "air fuel" OR lambda OR "air/fuel") AND heater. 62 unique complaints; every one read and coded (o2-heater-62-complaints-read.csv). The 62 include 15 that are not about an oxygen-sensor heater; they are kept in the file with that label.
   Result: 15 are not about an oxygen-sensor heater (seat heaters, cabin heaters, child seat, RV, and two false code matches). Of the 47 that are: 6 Chevrolet Volts with an EGR short and a shared fuse; 9 with an engine fault behind the heater code (coolant, oil, timing, misfire); 12 unresolved after sensors, software or dealer visits; 4 with wiring or connector damage found; 14 that list a heater code without a heater diagnosis; 2 inspection-readiness reports. Six name P0135 itself: five Volts and one Mercury Milan.

2. Honda 2023-2026 CR-V and Accord injector complaints (41, all read in full)
   Every complaint for a 2023-2026 Honda CR-V or Accord (any variant) whose narrative contains "injector". Coded in honda-2023-2026-crv-accord-injector-41-complaints.csv. "Says hybrid" means the model name or the text says hybrid, EV mode, or the engine starting from electric drive. None of the 41 names P0134 or P0135; one cites Honda bulletin 25-044.

3. Chevrolet Volt EGR complaints (172)
   Every Chevrolet Volt complaint whose narrative contains "EGR" as a whole word or "exhaust gas recirc". A first pass that matched the letters EGR anywhere caught words such as "degrees" and "integrated" and was corrected. All 172 are 2016-2018 models. Regular-expression flags for fuse, propulsion, P0135 (including "135" in a code list) and P0030/P0031 are in volt-egr-172-complaints-flags.csv.

4. Owner-reported amounts
   Dollar figures near oxygen-sensor wording in the 1,083 complaints that mention an O2, oxygen, A/F or air-fuel ratio sensor; figures listed only where the amount could be tied to the sensor, its wiring, or the cause documented in this guide. Bills, quotes and estimates as owners reported them, not invoices.

5. Documents
   p0135-recalls-extensions-bulletins.csv; each marked "yes" downloaded from static.nhtsa.gov and read in full on 25 September 2026. Ford TSB 14-0129's PDF is an image and was not read; only NHTSA's summary is used, and it is marked as such.

Limits: complaints over-represent bad outcomes; owners report warning messages more often than codes; one reader, one pass. Nothing here is a failure rate.