Check-engine codes
Look up any check-engine code — what it means for your car, what usually causes it, and whether you can keep driving.
AllTransmission · 142Wiring / network · 109Oxygen sensors · 85Fuel · 84Air intake · 74Sensors · 70Valve timing · 57Electrical · 35Emissions · 30Fuel vapour (EVAP) · 28Ignition · 28Cooling · 22Misfire · 16Turbo · 16Brakes / ABS · 10EGR · 10Air conditioning · 7Catalytic converter · 6Airbags / seat belts · 5
catalyst codes
P0420
Catalyst System Efficiency Below Threshold (Bank 1)
Catalytic converterMedium
P0421
Warm Up Catalyst Efficiency Below Threshold (Bank 1)
Catalytic converterMedium
P0422
Main Catalyst Efficiency Below Threshold (Bank 1)
Catalytic converterMedium
P0430
Catalyst System Efficiency Below Threshold (Bank 2)
Catalytic converterMedium
P0431
Warm Up Catalyst Efficiency Below Threshold (Bank 2)
Catalytic converterMedium
P0432
Main Catalyst Efficiency Below Threshold (Bank 2)
Catalytic converterMedium