# P0420 on the 1998 GMC Sonoma

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

- [10011129](https://open.wenmarpro.com/bulletins/10011129), 2005-01-03: SERVICE ENGINE SOON \(SES\) LIGHT ILLUMINATED, DIAGNOSTIC TROUBLE CODE P0420 SET. \*TT