P0174: System too lean (Bank 2)
Drive carefully. Get it checked within a week or two.
Can I drive with P0174?
Yes, but drive carefully and get it checked soon. Bank 2 is receiving extra unmetered air or insufficient fuel, causing stumbling and lean running.
What does P0174 mean?
P0174 stands for System Too Lean (Bank 2).
Symptoms you may notice
- Rough or vibrating idle when stopped in gear
- Hesitation or mild sputtering during initial acceleration
- Whistling or hissing noise from an intake vacuum leak
How much does it cost to fix?
Repair costs for code P0174 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:
- Vacuum leak along intake ducting or PCV elbow
- Dirty Mass Airflow (MAF) sensor
- Intake manifold gasket leaking on Bank 2
- Weak fuel delivery or clogged fuel filter
What to do next
- Inspect intake manifold gaskets and vacuum lines on the Bank 2 side.
- Clean the MAF sensor wire with specialized aerosol cleaner.
- Check fuel pressure with a mechanical gauge on the fuel rail.
Last updated: October 2026
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General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.
About this code
Code P0174 applies to V6, V8, or boxer engines where Bank 2 (the side without cylinder 1) runs lean. Very frequently, P0171 and P0174 appear together, confirming that the leak is before the manifold plenum (such as an intake accordion hose tear or a dirty MAF). Safe for short drives, but needs repair within a week to protect the exhaust catalyst.