What it means
Fuel control system B on bank 2 has detected a rich condition off idle. The code identifies the operating condition and fuel control system; it does not specify a particular injection type or cause.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Fuel control system B adjusts fueling for bank 2 based on air-fuel and oxygen sensor feedback. This code sets when bank 2 is detected running rich while the engine is off idle, indicating excess fuel or too little measured air in that operating range.
Common causes
Most likely first.
- Excessive fuel pressure
- Leaking or stuck-open injector
- Faulty air-fuel ratio or oxygen sensor
- Faulty fuel pressure regulator
- Restricted air intake
Symptoms
- Check engine light on
- Increased fuel consumption
- Black smoke from exhaust on acceleration
- Smell of unburned fuel, fouled spark plugs
How to diagnose it
- Save freeze-frame data and review bank 2 fuel trims and sensor readings at the off-idle conditions recorded for the fault.
- Inspect the air intake path for bank 2-related restrictions and check for wiring or sensor issues that could misreport incoming air or exhaust mixture.
- Look for evidence of a leaking or stuck-open injector on bank 2, such as wet plugs or a strong fuel smell after operation.
- Measure fuel pressure and check the pressure regulator according to manufacturer procedures, since excessive pressure can enrich the mixture.
- If fuel delivery checks out, test bank 2 air-fuel or oxygen sensor response and its wiring before replacing parts.
Common fixes
- Clear an intake restriction that is reducing measured airflow.
- Repair or replace a bank 2 injector confirmed to be leaking or stuck open.
- Repair the fuel pressure control fault if pressure exceeds the manufacturer's specification.
- Repair sensor wiring or replace a sensor only if testing confirms inaccurate feedback.
Can I keep driving?
Keep driving to a minimum and avoid high loads while bank 2 is running rich. Excess fuel can foul plugs and damage the catalytic converter; stop if smoke is heavy, the engine misfires, or fuel odor is strong.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.