Índice de códigos de avaria · medium
P0420
Catalytic converter system efficiency below threshold – bank 1
Catalytic converter system efficiency below threshold – bank 1
Documented for: 2.0L gasoline; 2.5L/3.0L gasoline · System(s): EMS EOBD, EMS OBD II · Factory MIL flag: 2
Common causes
- HO2 Sensor disconnected HO2 Sensor to ECM wiring fault HO2 Sensor heater to ECM wiring fault HO2 Sensor heater failure Upstream HO2 Sensor failure Downstream HO2 Sensor failure Catalyst failure
- Catalyst System Efficiency Below Threshold (Bank 1)
Quick checks
- Confirm freeze-frame and conditions when the code set
- Inspect connectors, grounds, and harness for the circuit named in the code
- Compare live sensor values vs expected (unplugged/biased sensors are common)
Typical fixes
- Check for exhaust leaks
- replace catalytic converter