P23FEBank 1 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
- P23FE reports a cylinder-to-cylinder imbalance on bank 1 that the control unit attributes to fuel system B, without naming a cylinder. Ford's 2024 OBD summary explains the letter for its dual-injection engines: the port path is Fuel Control System B with its own lean and rich codes (P2BF0/P2BF1 for bank 1), while direct injection forms system A. Ford's imbalance monitor itself still stores only P219A: it runs once per trip in closed loop after the fuel monitor has adapted, needs 300 to 700 s and fails above an imbalance ratio of 0.75. No manufacturer publishes P23FE. An inline engine has only bank 1, so the code then covers all its cylinders; on V engines it is the side with cylinder 1. A system-wide B code points to the port rail, its pressure or several port injectors at once.
- What you may notice
- Check engine light on
- Lean or rich fuel trim on bank 1, possibly P2BF0 or P2BF1
- Slightly increased fuel consumption
- Likely causes
- LikelySeveral port injectors on bank 1 fouled by deposits
- PossiblePort fuel rail pressure or low-pressure supply wrong on bank 1
- PossibleIntake manifold leak on the bank 1 side
- RareFront oxygen sensor of bank 1 responding poorly
- 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.