OBD-II code · Powertrain (generic, extended)
P21FC Fuel Control System B Too Lean at Higher Load (Bank 1)
Secondary fuel control loop B on bank 1 reports a lean condition at higher load. Lean at high load typically points at fuel pressure shortfall, restricted injectors, or charge-air leak.
Is it safe to drive with P21FC?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyFuel pressure drops under load
- PossibleCharge-air leak after turbo
Symptoms
- Check engine light on
- Rough idle, possible stalling
- Hesitation or hard cold start
- Power loss under load
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.7–5 h
- Emissions test
- Likely to fail
- Parts involved
- Fuel Pressure Regulator, Fuel Injector, Charge Air Pipe
Related codes
- P21F4Fuel Control System B Too Lean Off Idle (Bank 1)
- P21FEFuel Control System B Too Lean at Higher Load (Bank 2)
- P21F9Fuel Control System B Too Rich at Idle (Bank 1)
- P21FAFuel Control System B Too Lean at Idle (Bank 2)
- P21FBFuel Control System B Too Rich at Idle (Bank 2)
- P21FDFuel Control System B Too Rich at Higher Load (Bank 1)
- P21FFFuel Control System B Too Rich at Higher Load (Bank 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.