P0422 OBD II Trouble Code Main Catalyst Efficiency Below Threshold (Bank 1)
Detailed information on troubleshooting and repairing a P0422 DTC code which has to do with the catalyst system. Also includes links to relevant forum topics on the code.
Symptoms of P0422 OBD II Trouble Code
- Increased tailpipe emissions
- MIL (Malfunction Indicator Lamp) illumination
Common Causes of P0422 OBD II Trouble Code
- Bad or non-functional catalyst
- Engine operating out of optimal air:fuel ratio