P0420 on the 2016 Honda CR-Z
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.
| A22-040 | 2022-09-27. Service bulletin. Service Bulletin - The MIL is on with P0420 (Catalyst System Efficiency Below Threshold). Sensors on the vehicle may misinterpret the catalyst as deteriorated or it may have deteriorated. |
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1 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.