P2BF3
Fuel Control System B Too Rich Bank 2
Fuel control system B on bank 2 reports a persistently rich condition. Long-term fuel trim is at the negative limit, indicating excess fuel delivery or air metering error.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Increased fuel consumption
- Black smoke from exhaust on acceleration
- Smell of unburned fuel, fouled spark plugs
Common causes
Ordered by how often each turns out to be the cause.
- Fuel rail pressure high or regulator stuckCommon
- Injector leaking - over-fuellingPossible
Parts involved
- Fuel Injectors
- Fuel Pressure Regulator
- Intake System
P2BF3 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.