P0171 Chevrolet Traverse
System Too Lean (Bank 1) · Powertrain Code · High · Repair: Moderate
What is P0171?
The engine is running lean on bank 1 — too much air or not enough fuel. Common causes include vacuum leaks, weak fuel pump, clogged fuel injectors, or a faulty MAF sensor.
When the Chevrolet Traverse triggers code P0171 (system too lean (bank 1)), it typically points to an issue in the powertrain system. This is a high severity code, so address it promptly to avoid further damage or safety concerns. Below you'll find the most common causes, symptoms, and repair options specific to the Chevrolet Traverse.
This repair is rated moderate, meaning some experience and specialty tools required.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Chevrolet Traverse.
Common Causes on Chevrolet Traverse
- Intake manifold gasket leak on 3.6L V6 Traverse/Acadia causing lean condition
- PCV valve or hose failure creating vacuum leak on 3.6L LFY/LGX engine
- MAF sensor reading low from contamination or aftermarket air filter oil on 3.6L
- Fuel pressure drop from weak fuel pump module in high-mileage Traverse
- Cracked vacuum line to brake booster or EVAP purge valve on 3.6L V6
Symptoms
- Rough or unstable idle speed
- Hesitation or stumble during acceleration
- Engine surging or hunting at idle
- Lean misfire under load causing jerking
- Poor acceleration response and reduced power
- Check engine light illuminated
Notes for Chevrolet Traverse
The 3.6L V6 vacuum system has multiple potential leak points; a thorough smoke test is essential.