P21FFFuel Control System B Too Rich at Higher Load (Bank 2)
- 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
- P21FF closes the series: bank 2's second fuel path is rich in the upper load range although its correction already removes the largest reduction allowed. No manufacturer publishes criteria for it. Under CARB, a fuel system fault must be stored once adaptive control has exhausted the range the maker allows; threshold, load window and the number of trips are left to the manufacturer. On a V engine with dual injection, port injectors on bank 2 that over-deliver at long pulse widths, or excessive pressure in the shared low-pressure rail, would push this bank rich. If only bank 2 is affected, also compare the bank 2 front sensor signal with bank 1. Drivers rarely feel anything, but consumption rises. P2194 is the system A twin, P21FD the bank 1 code.
- What you may notice
- Check engine lamp on
- Increased fuel consumption
- Likely causes
- PossiblePort injectors on bank 2 over-delivering at long pulse widths
- PossibleBank 2 front oxygen sensor reading rich
- RareExcessive pressure in the shared low-pressure rail
- 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: €50 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.