P0420 Citroen Catalyst System Efficiency Below Threshold Bank 1

P0420 Citroen 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 Citroen code means…

P0420 Chrysler Catalyst System Efficiency Below Threshold Bank 1

P0420 Chrysler 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 Chrysler code means…

P0420 Chevrolet Catalyst System Efficiency Below Threshold Bank 1

P0420 Chevrolet 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 Chevrolet code means…

P0420 Cadillac Catalyst System Efficiency Below Threshold Bank 1

P0420 Cadillac 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 Cadillac code means…

P0420 Buick Catalyst System Efficiency Below Threshold Bank 1

P0421 Buick 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…

P0420 BMW Catalyst System Efficiency Below Threshold Bank 1

P0420 BMW 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 BMW code means…

P0420 Audi Catalyst System Efficiency Below Threshold Bank 1

P0420 Audi 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 Audi code means…

P0420 Acura Catalyst System Efficiency Below Threshold Bank 1

P0420 Acura 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 Acura code means…

P0420 Catalyst System Efficiency Below Threshold Bank 1

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…