P23F4Cylinder 3 Injector 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
- P23F4 refers to cylinder 3: the control unit has found that this cylinder burns leaner or richer than the others and traces the deviation to injector B. On a three-cylinder engine with port and direct injection, such as the Ford 1.5 EcoBoost, cylinder 3 is the last one; on four- and six-cylinder engines it lies in the middle of the block or bank. CARB lets a manufacturer store a misfire code instead of an imbalance code if exact identification would need extra hardware and misfire detection catches the fault reliably. A P0303 can therefore stand for the same cause. No maker documents P23F4 publicly. Port injectors that drip or clog and a leaking seal at the intake port of cylinder 3 should be checked first; P219E is the matching code without the injector letter.
- What you may notice
- Check engine light on
- Possible misfire code P0303 at the same time
- Uneven idle when the engine is warm
- Likely causes
- LikelyPort injector (injector B) of cylinder 3 dripping or partly blocked
- PossibleLeaking seal at the intake port of cylinder 3
- RareLow compression or leaking valves on cylinder 3
- 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 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.