P0421

Detection Condition:

Troubleshooting Hint:
Catalyst system monitor outline
- The catalyst monitors the deterioration of the catalytic converter in which the exhaust gas is purged. The catalyst monitor judges the deterioration of the catalytic convertor based on the oxygen concentration downstream side of the catalytic convertor each, are required.

Diagnostic Procedure (Steps 1 - 5):

Diagnostic Procedure (Steps 6 - 9):

Diagnostic Procedure (Steps 10 - 11):

Diagnostic Procedure (Steps 12 - 15):