P219B: Bank 2 Air/Fuel Ratio Imbalance
Severity: high
What it means: The engine computer sees that the air-fuel mixture is uneven between cylinders on bank 2 (the side opposite cylinder 1 on a V engine). One or more cylinders are getting too much or too little fuel or air.
Safe to drive? Usually OK for short trips if the engine runs smoothly and the check-engine light is steady. Get it checked soon. If the light flashes or the engine shakes, slow down and get it looked at right away, because misfires can damage the catalytic converter.
Common symptoms
- Check engine light or 'Emissions system problem' message
- Rough idle or loss of power
- Worse fuel economy
- Often shows up with misfire codes or P0430
Likely causes, ranked
- Fuel injector not spraying evenlyShop
- Large vacuum leakShop
- Faulty oxygen (air-fuel) sensor or wiringDIY
- Exhaust leak, MAF/MAP sensor fault, or weak fuel pumpShop
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Vehicle-specific notes
- 2016–2019 Honda Pilot: Owners with P219A or P219B plus P0430 and an 'Emissions system problem' message were often diagnosed with failing fuel injectors. Owners cite Honda service bulletin 20-100 and a VIN-specific warranty extension. Read the full answer · Source
DIY or shop?
DIY to read codes and check for vacuum hiss or damaged sensor wiring. Injector and fuel testing are shop jobs.
Before you replace parts
- Read all stored codes and fix misfire, MAF or MAP codes first.
- Listen for a vacuum hiss and look for damaged oxygen sensor wiring.
- Check your VIN for recalls, service bulletins and extended coverage. Some Honda V6 injector problems are covered by a warranty extension.
- Clear the code only after a repair, then confirm it stays off.
Safety / mechanic note
Verify with a mechanic. A code points to a system, not always a specific part.
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