Bad Catalytic Converter Symptoms in NHTSA Records, and Quote Lines
Manufacturer bulletins filed with NHTSA describe catalytic converter concerns as an exhaust smell or leak, an illuminated malfunction indicator lamp with code P0420, or increased tailpipe emissions. These are reported conditions for specific vehicles, not a diagnosis.
Conditions described in NHTSA records.
- Exhaust smell
Bulletin 10190310 (17-NA-321): CADILLAC XTS 2013-2018, CHEVROLET IMPALA 2014-2018 - Exhaust leak
Bulletin 10190310 (17-NA-321): CADILLAC XTS 2013-2018, CHEVROLET IMPALA 2014-2018 - Illuminated malfunction indicator lamp with diagnostic trouble code P0420
Bulletin 10241542 (TSB 23-2259): FORD BRONCO SPORT 2021-2023, FORD ESCAPE 2020-2022 - Increased tailpipe emissions; vehicle could fail an emissions inspection
Bulletin 10217845 (DC_26M4_26N6, filed 5 times): VOLKSWAGEN ATLAS 2018 - MIL on; other symptoms include poor acceleration
Bulletin 10230386 (T-TT-0718-22): TOYOTA TUNDRA 2022, TOYOTA TUNDRA HYBRID 2022 - MIL on condition that could involve deteriorated catalyst material from the bank 1 or bank 2 catalytic converter
Bulletin 10220186 (TTT069822): TOYOTA HIGHLANDER 2017-2022, TOYOTA SIENNA 2017-2020 - Check engine malfunction indicator lamp may illuminate (bulletin attributes it to sulfur contamination in the catalyst)
Bulletin 10237240 (ELW-M278Catalyst): MERCEDES-BENZ CL550 2011-2014, MERCEDES-BENZ CLS 550 2016-2018, MERCEDES-BENZ CLS550 2011-2017 and 4 other models - Catalytic converter or oxygen sensor performance degradation without illumination of the check engine light, as a result of excessive engine oil consumption
Bulletin 10183216 (N192287100): CHEVROLET EQUINOX 2012-2013, GMC TERRAIN 2012-2013 - In the event of a catalytic converter failure, existing diagnostics may not properly illuminate the MIL
Bulletin 10198238 (Dealer 24GQ): AUDI A3 2019-2020, AUDI Q3 2021, AUDI TT 2019-2021 - May exceed NOx emission level standards due to loss of catalytic converter efficiency
Bulletin 10230438 (U67): CHRYSLER 200 2011-2014, DODGE AVENGER 2011-2014, DODGE CALIBER 2011-2012 and 3 other models
What NHTSA records show.
- 2 light-vehicle recalls received since January 1, 2016 name this part in their title; 0 of them carry the NHTSA “Do Not Drive” advisory.
- 29 manufacturer communications (revisions and joint re-filings counted once) received by NHTSA in 2020-2024 (light vehicles only) are filed under this part.
- Models named most often in these communications, model years 2006-2023: CHEVROLET EQUINOX 2012-2022 (2 communications); CHRYSLER 200 2011-2016 (2 communications); GMC TERRAIN 2012-2022 (2 communications); VOLKSWAGEN ATLAS 2018-2019 (2 communications).
- By make: CHEVROLET 6, FORD 4, GMC 4.
- Recalls by manufacturer: BMW of North America, LLC 1, Kia America, Inc. 1.
“A loose connection between the exhaust system and catalytic converter increases the risk of a fire.”
“Some 2020-2022 Escape built and 2021-2023 Bronco Sport vehicles, built on or before 28-Sep-2022, equipped with a 1.5L Ecoboost engine and a 8F35 transmission may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble code (DTC) P0420 stored in the powertrain control module (PCM). This may be due to the catalytic converter. …”
“TT: Some 22MY Tundra/HV vehicles may experience a MIL ON w/DTC(s) P017400, P043000. Other symptoms of this issue include poor acceleration. A lean condition may cause damage to the internal catalyst in the catalytic converter.”
Checked on October 13, 2026.
Lines of a catalytic converter replacement quote.
| Line on the quote | In the tool |
|---|---|
| Catalytic converter | Listed |
| Oxygen sensors | Listed |
| Gaskets, bolts or clamps | Listed |
| Diagnosis | Listed |
| Labor | Listed |
| Shop supplies / disposal fees | Listed |
| Tax written on the quote | Listed |
| Coupon, discount or credit | Listed |
| Questions to ask the shop |
|---|
| What tests, beyond the trouble code, show that the converter itself needs replacing? |
| Is the vehicle still within its federal or state emissions warranty? |
| Is the quoted converter original equipment or aftermarket, and which approval does it carry for my state? |
| Which converter is this, and how many does the vehicle have? |
| Are the oxygen sensors, gaskets and hardware new or reused? |
| Is the converter new or used? |
Where the facts come from.
- National Highway Traffic Safety Administration (U.S. Department of Transportation) — Manufacturer communications received by NHTSA 2020-2024 (TSBS_RECEIVED_2020-2024, flat file) (opens an external site)
- National Highway Traffic Safety Administration (U.S. Department of Transportation) — Recalls, NHTSA via U.S. DOT open data (Socrata 6axg-epim) (opens an external site)
What this page cannot tell you.
- RepairWorth does not inspect vehicles, identify a fault from symptoms or recommend a repair.
- NHTSA counts cover light vehicles (cars, SUVs, light pickups and vans) filed with the agency; they are not failure rates.
Content status: Editorial review: AI-assisted, each condition and count checked against the NHTSA records cited, then four adverse QA passes, October 15, 2026; not a diagnosis.