P0174 – System Too Lean (Bank 2)
Want to confirm the real cause of this fault code?
A high‑quality OBD2 scanner gives you live data, fuel trims, sensor readings and freeze‑frame information — exactly what you need to verify the root cause of this code with confidence.
Symptoms
- Rough idle
- Hesitation
- Lack of power
- Poor fuel economy
- Possible misfires
Causes
- Vacuum leak on Bank 2 side
- Dirty or faulty MAF sensor
- Weak fuel pump or clogged filter
- Exhaust leak before Bank 2 O2 sensor
Diagnosis
- Compare Bank 1 and Bank 2 fuel trims
- Smoke-test intake and Bank 2 gaskets
- Check MAF data vs RPM
- Measure fuel pressure under load
Repair
- Repair Bank 2 intake or vacuum leaks
- Clean or replace MAF sensor
- Correct fuel delivery issues
- Repair exhaust leaks before O2 sensor
