This article supersedes TSB 21-2021 to update the part list Some 2019-2020 Ranger vehicles 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 various software parameters within the PCM. To correct the condition, follow the Service Procedure to reprogram the PCM and replace the catalytic converter.
