Diagnosis & Repair
WARNING: This page is about a different variant/trim than selected.
- If codes other than P0420 are present, diagnose and repair those codes first. If DTC P0420 is only displayed, check oxygen sensor No. 1. See DTC P0130: OXYGEN SENSOR CIRCUIT (SENSOR NO. 1) circuit test. Repair as necessary. If oxygen sensor circuits are okay, go to next step.
- Check oxygen sensor No. 2 circuits. See DTC P0136: OXYGEN SENSOR CIRCUIT (SENSOR NO. 2) circuit test. Repair as necessary. If oxygen sensor circuits and sensor are okay, replace catalytic converter and retest.