● Fix soon
Usually drivable for a short time, but check it soon. It can get worse.
Usually drivable for a short time, but check it soon. It can get worse.
The mixture on bank 1 has too much fuel or too little air. The driver may notice high consumption, a fuel smell from the exhaust or black smoke.
Guided check
- Is the air filter blocked or the MAF dirty?If yes: Replace the filter or clean the MAF, then check fuel trims again.
- Is the fuel pressure above the maker's value?If yes: Check the regulator and return line where fitted.
- Do the injectors leak when the engine is off?If yes: Replace or clean the leaking injector. Check the engine oil for fuel.
These checks are general and are still being reviewed by working mechanics.
Causes vary by car. Test before you order a part.
Likely causes, most common first
- Leaking fuel injector
- Excessive fuel pressure
- Dirty or faulty MAF sensor
- Saturated EVAP purge or clogged air filter
Parts usually involved
- Fuel injectors Find at suppliers
- Fuel pressure regulator Find at suppliers
- MAF sensor Find at suppliers
- Air filter Find at suppliers
Test before you replace
Check fuel trims, fuel pressure and the purge valve, and look for leaking injectors before replacing a sensor.
General guidance for generic OBD2 codes. Always follow the maker's procedure for the car in front of you.