# P0420 on the 2002 Cadillac Deville

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

- [10002446](https://open.wenmarpro.com/bulletins/10002446), 2003-08-29: SERVICE ENGINE SOON \(SES\) LIGHT ON, REDUCED VEHICLE POWER / ACCELERATION / SPEED, DIAGNOSTIC TROUBLE CODE \(DTC\) P0420. \*TT
- [629674](https://open.wenmarpro.com/bulletins/629674), 2002-04-04: CONCERNS WITH DIAGNOSTIC CODES P0420, CONVERTER EFFICIENCY, P0121 TPS PERFORMANCE AND P0133 AND P0153, O2 SENSOR SLOW RESPONSE. \*TT