Operation CHARM: Car repair manuals for everyone.

Diagnostic Procedure

DIAGNOSTIC PROCEDURE

1. Are there any other codes (besides Diagnostic Trouble Code P0420) being output?
- If NO proceed to step 2.
- If YES go to relevant Diagnostic Trouble Code chart.
2. Check Heated Oxygen Sensor.
- If OK eplace Three Way Catalytic Converter.
- If not OK repair or replace.