P0174 System Too Lean (Bank 2)
What does P0174 mean?
P0174 — System Too Lean (Bank 2) (bank 2). This is an OBD-II diagnostic trouble code a scanner retrieves when your vehicle's computer detects system too lean (bank 2) on bank 2. The level of risk depends on how the vehicle is currently running and how long you've been driving with the light on.
Common causes of P0174
- Vacuum leak on the bank 2 side of the intake
- Clogged or faulty injectors on bank 2
- Dirty or failing mass air flow sensor
- Low fuel pressure or weak fuel pump
- Faulty bank 2 oxygen sensor
How to fix P0174
- Smoke test for vacuum leaks affecting bank 2 cylinders
- Compare fuel trims between banks on an OBD-II scanner to isolate the side
- Check bank 2 fuel injectors for clogging or leaks
- Verify fuel pressure and MAF sensor performance
- Replace the bank 2 O2 sensor if it is slow or biased lean