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P0174: System Too Lean (Bank 2)
Severity: Medium Drive gently and get it diagnosed soon.
What does P0174 mean?
Same as P0171 but on bank 2 (the side of a V engine without cylinder 1). If both P0171 and P0174 are set, look for a shared cause such as a vacuum leak, MAF sensor, or fuel delivery.
Generic OBD-II definition: System Too Lean (Bank 2). Confirm applicability in your vehicle service information.
Common causes
- Vacuum leak
- Dirty or faulty MAF sensor
- Low fuel pressure
- Exhaust leak before the O2 sensor
Symptoms
- Rough idle
- Hesitation
- Possible misfires
Can I keep driving with P0174?
Severity: Medium Drive gently and get it diagnosed soon.
If the check engine light is flashing or the car runs badly, stop driving and have it checked.
Typical fixes
- Check for vacuum leaks
- Clean or test the MAF
- Check fuel pressure