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P0420 on the 2018 Mack Anthem

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

Nobody has written a description of this code yet.

Bulletins for this model year that name P0420
KC-1682022-04-05. Service bulletin. Mack Chassis - Diagnostic Trouble Code ( DTC ) P0420 Illuminating The Malfunction Indicator Lamp (MIL) - US17+OBD16 And US17+OBD18 (GHG17) Emissions (Common Rail Fuel System) - Commonly Model Years 2018 And 2019
KC-1682021-12-07. Service bulletin. Mack Chassis - Diagnostic Trouble Code ( DTC ) P0420 Illuminating The Malfunction Indicator Lamp (MIL) - US17+OBD16 And US17+OBD18 (GHG17) Emissions (Common Rail Fuel System) - Commonly Model Years 2018 And 2019
K559052212018-07-16. Service bulletin. Mack Chassis - Diagnostic Trouble Code ( DTC ) P0420 Illuminating The Malfunction Indicator Lamp (MIL) - US17+OBD16 And US17+OBD18 (GHG17) Emissions (Common Rail Fuel System) - Commonly Model Years 2018 And 2019
K559052212018-06-18. Service bulletin. Mack Chassis - Diagnostic Trouble Code ( DTC ) P0420 Illuminating The Malfunction Indicator Lamp (MIL) - US17+OBD16 And US17+OBD18 (GHG17) Emissions (Common Rail Fuel System) - Commonly Model Years 2018 And 2019
K559052212018-05-29. Service bulletin. Mack Chassis - Diagnostic Trouble Code ( DTC ) P0420 Illuminating The Malfunction Indicator Lamp (MIL) - US17+OBD16 And US17+OBD18 (GHG17) Emissions (Common Rail Fuel System) - Commonly Model Years 2018 And 2019
K043423272018-03-19. Service bulletin. Diagnostic Trouble Code ( DTC ) P0420 Illuminating The Malfunction Indicator Lamp (MIL) - US17 (GHG17, Common Rail Fuel System) Chassis ONLY

6 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.