P0420 on Ford vehicles The catalytic converter on bank 1 is not cleaning up the exhaust as well as it should

A model year is listed because the code is named in its own record — a bulletin filed against it, or an owner’s complaint about it — not because every one of these vehicles sets it. Counts are documents in NHTSA’s files, not failure rates.

Bulletins and campaigns Ford filed with NHTSA whose summary names P0420. Quote the document number at the service desk — it is a diagnosis the maker has already written down.

• TSB 23-2337 Service bulletin
  2023-10-31 · Engine And Engine Cooling
• Some 2022-2023 F-150 hybrid vehicles equipped with a 3.5L PowerBoost engine may exhibit an illuminated MIL with diagnostic trouble codes (DTCs) P0420 and/or P0430 stored in the powertrain control module (PCM). This may be due to high sulfur content in the fuel. To correct the condition, follow the Service Procedure to remove sulfur from the catalytic converters.
• TSB 23-2425 Service bulletin
  2023-12-20 · Power Train — Automatic Transmission — Control Module (Tcm/Pcm/Tecm)
• This article supersedes TSB 23-2337 to update the Service Procedure and the causal part. Some 2022-2023 F-150 hybrid vehicles equipped with a 3.5L PowerBoost engine may exhibit an illuminated MIL with diagnostic trouble codes (DTCs) P0420 and/or P0430 stored in the powertrain control module (PCM). This may be due to high sulfur content in the fuel. To correct the condition, follow the Service Proc
• TSB 24-2124 Service bulletin
  2024-04-26 · Power Train
• This article supersedes TSB 23-2425 to address revised software and update the Parts List. Some 2022-2023 F-150 hybrid vehicles equipped with a 3.5L PowerBoost engine may exhibit an illuminated MIL with diagnostic trouble codes (DTCs) P0420 and/or P0430 stored in the powertrain control module (PCM). This may be due to calibration and controls sensitivity. To correct the condition, follow the Servi
• TSB 25-2119 Service bulletin
  2025-03-26 · Unknown Or Other
• Some of the vehicles listed in the Model statement above may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P0420 and/or P0430 stored in the powertrain control module (PCM). This may be due to the software in the PCM.
• TSB 25-2549 Service bulletin
  2025-11-06 · Electrical System
• This article supersedes TSB 25-2119 to update the vehicles affected, parts list, and Service Procedure. Some of the vehicles listed in the Model statement above may exhibit an incorrectly illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P0420 and/or P0430 stored in the powertrain control module (PCM). This may be due to the software in the PCM. This condition does n
• TSB 26-2216 Service bulletin
  2026-05-06 · Power Train
• This bulletin supersedes 25-2549. Reason for update: To add 2020 model year chassis cab vehicles. Some of the vehicles listed in the Model statement above may exhibit an incorrectly illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P0420 and/or P0430 stored in the powertrain control module (PCM). This may be due to the software in the PCM. This condition does not aff
• TSB 23-2259 Service bulletin
  2023-08-16 · Engine And Engine Cooling — Exhaust System — Emission Control — Catalytic Convertor
• 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. To correct this condition, follow the Service Proc
• TSB 25-2407 Service bulletin
  2025-08-29 · Power Train
• * This article supersedes TSB 25-2269 to update vehicles affected. Some of the vehicles listed in the Model statement above may exhibit an incorrectly illuminated malfunction indicator lamp (MIL) with diagnostic trouble code (DTC) P0420 stored in the powertrain control module (PCM). This may be due to the software in the PCM.
• SSM 49996 Service bulletin
  2021-08-03 · Engine And Engine Cooling
• Some 2021 Bronco Sport vehicles equipped with a 1.5L EcoBoost engine may exhibit a no crank/no start start condition with an illuminated malfunction indicator lamp (MIL) and one or more of the following diagnostic trouble codes (DTC): P093B, P2282, P0420, P062B, P21D1, P21D0, P21CF, P0710, and/or P0712. This may be due to a damaged wiring harness at the transmission cover. If damage is found, repa
• TSB 25-2348 Service bulletin
  2025-07-25 · Power Train
• Some of the vehicles listed in the Model statement above may exhibit an incorrectly illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P0128, P0420, and/or P0430 stored in the powertrain control module (PCM). This may be due to the software in the PCM.
• TSB 25-2382 Service bulletin
  2025-08-20 · Power Train
• Some of the vehicles listed in the Model statement above may exhibit an incorrectly illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P0420 and/or P0430 stored in the powertrain control module (PCM). This may be due to the software in the PCM.
• TSB 25-2269 Service bulletin
  2025-06-14 · Power Train
• Some of the vehicles listed in the Model statement above may exhibit an incorrectly illuminated malfunction indicator lamp (MIL) with diagnostic trouble code (DTC) P0420 stored in the powertrain control module (PCM). This may be due to the software in the PCM.

A stored code names the test that failed, never the part that caused it. The record above is what Ford and its owners have filed about it; the code’s page across every make has the whole file.