System Inspection

P0420 Catalyst System Efficiency below Threshold (Bank1)

Inspection/Repair - System Inspection

System Inspection

1. Exhaust gas system check
(1) Visual check
- Check air leakage at junction of HO2S or Catalyst converter.
- Check looseness, poor connection, or damage.
(2) Is there something wrong?
YES
1) Repair as necessary and then, go to "Verification of Vehicle Repair" procedure.
NO
1) Go to "Component inspection" procedure.