Catalyst Monitoring

Condition(s):

DTC P0420 Catalyst system efficiency below threshold (Bank 1)

Possible Source(s):
- Catalyst failure
- Upstream O2 sensor failure
- Downstream O2 sensor failure
- O2 sensor heater failure
- Associated harness/connector failure

Action(s) to take:
- See DTC P0137, P0138 P0137 and P0140 P0140

DTC P0430 Catalyst system efficiency below threshold (Bank 2)

Possible Source(s):
- Catalyst failure
- Upstream O2 sensor failure
- Downstream O2 sensor failure
- O2 sensor heater failure Associated harness/connector failure

Action(s) to take:
- See DTC P0157, P0158 P0157 and P0160 P0160