P0174
System Too Lean Bank 2
Powertrain · Generic (all makes)System: Intake Air/Vacuum + Fuel Delivery
Fix within days. Damage or fuel waste builds up.
Likely causes
- Vacuum leak on bank 2
- Dirty or failing mass air flow sensor
- Low fuel pressure
- Exhaust leak ahead of the bank 2 oxygen sensor
What to check first
Both banks lean (P0171 and P0174 together) usually points to a shared cause: a large vacuum leak, the MAF sensor or fuel pressure.
Typical repair cost
$100 – $500
Independent-shop parts and labor for the usual fix. Your price depends on the actual cause and the vehicle.
Next step
General information, not a diagnosis of your vehicle. Repair costs are typical shop ranges, not quotes.