p0171
Moderate
Chevrolet · SUVs
System Too Lean Bank 1
Quick Answer
Error code P0171 on your Chevrolet SUVs means: System Too Lean Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Vacuum leak in intake manifold or hoses
  2. Dirty or faulty mass airflow (MAF) sensor
  3. Weak fuel pump or clogged fuel filter
  4. Leaking fuel injectors
  5. Exhaust leak upstream of the O2 sensor
How to Fix It
1
Inspect intake manifold and all vacuum hoses for cracks, splits, or disconnections
2
Remove and clean the MAF sensor with MAF-specific cleaner; replace if damaged
3
Test fuel pressure at the rail with a fuel pressure gauge
4
Check for exhaust leaks at the exhaust manifold and upstream O2 sensor area
5
Clear the code and test drive to confirm the repair
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
MAF sensor or MAF cleaner
Vacuum hoses
Fuel filter
Intake manifold gaskets
Related Error Codes
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