What does code P21FD mean?

Q: What does code P21FD mean?

Fuel Control System B Too Rich at Higher Load (Bank 1). P21FD means the powertrain control module has detected that the air-fuel mixture on bank 1 is too rich when the engine is under higher load, based on oxygen sensor feedback that stays biased toward rich. The computer is reporting that more fuel is being delivered than can be burned with the air available, specifically in the higher-load operating range rather than at idle or cruise.

DTC codes / P21xx · Fuel and air metering / P21FD

P21FDFuel Control System B Too Rich at Higher Load (Bank 1)

P21FD means the powertrain control module has detected that the air-fuel mixture on bank 1 is too rich when the engine is under higher load, based on oxygen sensor feedback that stays biased toward rich. The computer is reporting that more fuel is being delivered than can be burned with the air available, specifically in the higher-load operating range rather than at idle or cruise.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaFuel and air metering

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.