OBD-II code · Powertrain (generic, extended)
P21F7 Fuel Control System B Too Rich Off Idle (Bank 2)
The secondary fuel control loop B on bank 2 reports a rich condition outside idle.
Is it safe to drive with P21F7?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyInjectors leaking
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
- 0.7–4 h
- Emissions test
- Likely to fail
- Parts involved
- Fuel Injector
Related codes
- P21F5Fuel Control System B Too Rich Off Idle (Bank 1)
- P21F4Fuel Control System B Too Lean Off Idle (Bank 1)
- P21F6Fuel Control System B Too Lean Off Idle (Bank 2)
- P21F8Fuel Control System B Too Lean at Idle (Bank 1)
- P21F9Fuel Control System B Too Rich at Idle (Bank 1)
- P21FAFuel Control System B Too Lean at Idle (Bank 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.