OBD-II code · Powertrain (generic, extended)
P21FF Fuel Control System B Too Rich at Higher Load (Bank 2)
The secondary fuel control loop B reports a rich condition at higher load on bank 2. Rich at high load typically points to a stuck-closed return on the fuel pressure regulator or over-delivering injectors.
Is it safe to drive with P21FF?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyInjectors over-deliver on bank 2
Symptoms
- Check engine light on
- Increased fuel consumption
- Black smoke from exhaust on acceleration
- Smell of unburned fuel, fouled spark plugs
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 Injector
Related codes
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.