What does code P21F6 mean?

Q: What does code P21F6 mean?

Fuel Control System B Too Lean Off Idle (Bank 2). P21F6 indicates that the engine computer has detected an excessively lean air-fuel mixture on bank 2 while the engine is running above idle, based on oxygen sensor feedback that stays lean beyond a calibrated threshold. The powertrain control module (PCM) sets this code when its fuel trim corrections for bank 2 reach a positive limit and the exhaust oxygen sensor continues to report a lean condition off idle.

DTC codes / P21xx · Fuel and air metering / P21F6

P21F6Fuel Control System B Too Lean Off Idle (Bank 2)

P21F6 indicates that the engine computer has detected an excessively lean air-fuel mixture on bank 2 while the engine is running above idle, based on oxygen sensor feedback that stays lean beyond a calibrated threshold. The powertrain control module (PCM) sets this code when its fuel trim corrections for bank 2 reach a positive limit and the exhaust oxygen sensor continues to report a lean condition off idle.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

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.