P0421 Citroen Warm Up Catalyst Efficiency Below Threshold Bank 1

P0421 Citroen 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 Chrysler Warm Up Catalyst Efficiency Below Threshold Bank 1

P0421 Chrysler 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 Chevrolet Warm Up Catalyst Efficiency Below Threshold Bank 1

P0421 Chevrolet 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 Cadillac Warm Up Catalyst Efficiency Below Threshold Bank 1

P0421 Cadillac 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 Buick Warm Up Catalyst Efficiency Below Threshold Bank 1

P0423 Buick Heated Catalyst Efficiency Below Threshold Bank 1 Possible causes – Air leak before catalytic converter – Faulty oxygen sensor– Faulty Catalytic Converter Tech description As the code description implies the P0423 Buick code means that the vehicle’s control module has detected that the three-way catalytic converter is not working properly (is not as…

P0421 BMW Warm Up Catalyst Efficiency Below Threshold Bank 1

P0421 BMW 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 Audi Warm Up Catalyst Efficiency Below Threshold Bank 1

P0421 Audi 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 Acura Warm Up Catalyst Efficiency Below Threshold Bank 1

P0421 Acura 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 Warm Up Catalyst Efficiency Below Threshold Bank 1

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…