P23FFBank 2 System B Air-Fuel Ratio Imbalance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P23FF mirrors P23FE for bank 2 and can only occur on V, W or boxer engines, because inline engines have no second bank. It means the cylinders on the side without cylinder 1 deviate from each other and the fault is assigned to injection system B, which on Ford's PFDI engines is the port path (lean and rich codes P2BF2/P2BF3). Bank-level monitors on such engines are documented, but under the general codes: GM's 2019 LT5 Corvette V8 fails bank 2 when the normalised oxygen sensor ratio exceeds 0.75, rated Type A and lighting the MIL on the first failed trip, and Ford sets P219B. No manufacturer publishes P23FF. When the fault stays confined to bank 2, the culprit usually sits on that side, such as a port fuel rail, a manifold gasket or several injectors of that bank.
- What you may notice
- Check engine light on
- Fuel trims of the two banks clearly apart
- Possibly P2BF2 or P2BF3 as well
- Likely causes
- LikelySeveral port injectors on bank 2 with deposits or wear
- PossibleIntake manifold gasket leaking on bank 2
- RareSupply problem in the port fuel rail feeding bank 2
- RareFront oxygen sensor or its wiring on bank 2 distorting the signal
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.