What does code P0171 mean?
The air fuel mixture is too lean on bank 1; excess air or insufficient fuel
OBD-II Code
P0171 — System Too Lean Bank 1
The air fuel mixture is too lean on bank 1; excess air or insufficient fuel
Common symptoms
- Loss of power
- hesitation
- increased fuel consumption
- hard starting
Possible causes
- Vacuum leak
- dirty MAF sensor
- low fuel pressure
- clogged fuel filter
Initial recommendation
Check hoses, clean MAF sensor, inspect fuel filter and fuel pressure.
Safety notice
This information is for guidance only and does not replace a physical vehicle inspection or diagnosis by a qualified mechanic. If the vehicle has severe power loss, smoke, a fuel odor, overheating, brake or steering problems, or any unsafe behavior, avoid driving it and seek professional inspection.
Analyze this code with MecaOBD
Use the app to combine code P0171 with your vehicle's actual symptoms for more complete diagnostic guidance.
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