P0421
Warm up catalyst efficiency below threshold, bank 1
- System
- Powertrain - engine and transmission
This is a standard code. It means the same thing on every make of vehicle.
Related codes
- P0400Exhaust gas recirculation flow
- P0401Exhaust gas recirculation flow insufficient
- P0402Exhaust gas recirculation flow excessive
- P0403Exhaust gas recirculation control circuit
- P0404Exhaust gas recirculation control circuit range
- P0405Exhaust gas recirculation sensor A circuit low
- P0406Exhaust gas recirculation sensor A circuit high
- P0410Secondary air injection system