DTC P0420 Or P0430: Catalyst System: Notes
DTC IDENTIFICATION
| DTC | Affected Circuit |
|---|---|
| P0420 | Catalyst System Efficiency Below Threshold (Bank 1) |
| P0430 | Catalyst System Efficiency Below Threshold (Bank 2) |
CAUTION:
If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction.