Severity: Moderate
Drivable, but it can cause more damage or poor economy. Get it checked within days.
What P0174 means
Bank 2 is running lean. If P0171 is also set, look for something both banks share: a large vacuum leak, the MAF sensor or fuel supply.
Symptoms
- Rough idle
- Hesitation
- Poor fuel economy
Common causes
Most likely first
- 1Vacuum leak
- 2Dirty MAF sensor
- 3Low fuel pressure
- 4Intake manifold gasket leak on bank 2
How we diagnose it
- Fuel trims both banks
- Smoke test
- Fuel pressure test
Every vehicle sets codes under its own conditions. We check the factory diagnostic steps and service bulletins for your VIN, so the repair targets the actual cause.