# P0420 on the 2023 Honda Civic

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

- [11011792](https://open.wenmarpro.com/bulletins/11011792), 2024-12-12: Dealer Message \- American Honda Motor Co., Inc. \(AHM\) is searching for certain 2018\-2024 Accord 1.5Ls, 2021\-2024 Civics 1.5Ls, 2023\-2024 CR\-Vs 1.5Ls, and 2017 Fits with customer complaint of Check Engine Light \(CEL\) on with DTC P0420 \[Catalyst System Efficiency Below Threshold\] stored. To better understand the cause of this condition, AHM would like to specific parts from the vehicle prior to you attempting a repair of any kind.
- [11010549](https://open.wenmarpro.com/bulletins/11010549), 2024-11-14: Dealer Message \- American Honda Motor Co., Inc. \(AHM\) is searching for certain 2018\-2024 Accord 1.5Ls, 2021\-2024 Civics 1.5Ls, 2023\-2024 CR\-Vs 1.5Ls, and 2017 Fits with customer complaint of Check Engine Light \(CEL\) on with DTC P0420 \[Catalyst System Effciency Below Threshold\] stored. To better understand the cause of this condition, AHM would like to specific parts from the vehicle prior to you attempting a repair of any kind.