P23FDCylinder 12 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
- P23FD closes the cylinder series at number 12. It states that the twelfth cylinder runs out of step with the rest and that the cause lies with its injector B. A matching engine needs twelve cylinders and two injectors in each, a combination that public engine references do not show: the VW W12, for instance, appeared with port injection and later as the 6.3 FSI with direct injection only. CARB nonetheless expects every petrol engine to detect imbalance that would lift emissions beyond the limits, and lets the stored code stay at bank or misfire level when the method cannot single out one cylinder. No manufacturer documents P23FD. On a V12 or W12 that stores it, compare the bank codes P23FE/P23FF and P219A/P219B with P21A7, P0312 and P21DA.
- What you may notice
- Check engine light on
- Bank or misfire code stored at the same time
- Likely causes
- PossibleSecond injector of cylinder 12 out of tolerance
- PossibleIntake leak or valve sealing fault at cylinder 12
- RareCode reported by a tool on an engine without a second injector
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €200 – €1,800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.