Category: OBDii Powertrain Codes

P0439 Catalyst Heater Control Circuit Bank 2 Possible causes – Catalyst Temperature Sensor harness is open or shorted– Catalyst Temperature Sensor circuit poor electrical connection– Faulty Catalyst Temperature Sensor Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P0439 Description The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen…

P0430 Catalyst System Efficiency Below Threshold Bank 2 Possible causes – Three way catalyst converter Bank 2– Exhaust tube– Intake air leaks– Fuel injectors may be faulty– Fuel injector leaks– Spark plugs may be faulty– Improper ignition timing– Engine Control Module (ECM) Tech description As the code description implies the P0430 code means that the…

P0431 Warm Up Catalyst Efficiency Below Threshold Bank 2 Possible causes – Warm Up Three Way Catalytic converter deterioration or malfunction– Exhaust system leaks– Loose front or rear HO2Ss– Faulty front heater O2 sensor– O2 sensors harness is open or shorted– O2 sensors poor electrical connection Tech description As the code description implies the P0431…

P0432 Main Catalyst Efficiency Below Threshold Bank 2 Possible causes – Warm Up Three Way Catalytic converter deterioration or malfunction– Exhaust system leaks– Loose front or rear HO2Ss– Faulty front heater O2 sensor– O2 sensors harness is open or shorted– O2 sensors poor electrical connection Tech description As the code description implies the P0432 code…

P0433 Heated Catalyst Efficiency Below Threshold Bank 2 Possible causes – Air leak before catalytic converter– Faulty oxygen sensor– Faulty Catalytic Converter Tech description As the code description implies the P0433 code means that the vehicle’s control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the…

P0428 Catalyst Temperature Sensor High Input Bank 1 Sensor 1 Possible causes – Faulty Catalyst Temperature Sensor– Catalyst Temperature Sensor harness is open or shorted– Catalyst Temperature Sensor circuit poor electrical connection Tech description As the code description implies the P0428 code means that the vehicle’s control module has detected that the three-way catalytic converter…

P0429 Catalyst Heater Control Circuit Bank 1 Possible causes – Faulty Catalyst Temperature Sensor– Catalyst Temperature Sensor harness is open or shorted– Catalyst Temperature Sensor circuit poor electrical connection Tech description As the code description implies the P0429 code means that the vehicle’s control module has detected that the three-way catalytic converter is not working…

P0420 Catalyst System Efficiency Below Threshold Bank 1 Possible causes – Three way catalyst converter Bank 1– Exhaust tube– Intake air leaks– Fuel injectors may be faulty– Fuel injector leaks– Spark plugs may be faulty– Improper ignition timing– Engine Control Module (ECM) Tech description As the code description implies the P0421 code means that the…

P0421 Warm Up Catalyst Efficiency Below Threshold Bank 1 Possible causes – Warm Up Three Way Catalytic converter deterioration or malfunction– Exhaust system leaks– Loose front or rear HO2Ss– Faulty front heater O2 sensor– O2 sensors harness is open or shorted– O2 sensors poor electrical connection Tech description As the code description implies the P0421…