P0171 on a 2017 Chevrolet Traverse

P0171 means the engine computer is adding more fuel than normal on bank 1 because it sees too much air or not enough fuel.

Not your vehicle? See general P0171 info.

Most common causes on the 2017 Chevrolet Traverse

Ranked from 358 NHTSA owner complaints filed for this vehicle.

Sort by:

1
Weak or failing fuel pump
High severity
Two owners describe surging on acceleration and stalling at idle tied to the GM low-pressure fuel pump defect/recall — a textbook lean-condition cause from inadequate fuel delivery.
Reported in 2 NHTSA complaints
Parts:fuel pump
2
EVAP purge valve stuck open
Medium severity
Two owners describe EVAP canister purge control valve faults/codes on this vehicle; a purge valve stuck open pulls extra, unmetered air/vapor into the intake and can push fuel trims lean.
Reported in 2 NHTSA complaints
Parts:purge valve
3
Vacuum or intake manifold gasket leak
Medium severity
Unmetered air drawn in past the MAF sensor skews the mixture lean, especially noticeable at idle; a smoke test will find the leak point.
Common cause
Parts:intake manifold gasket vacuum hose
4
Dirty or failing MAF sensor
Medium severity
A contaminated or drifting MAF under-reports incoming air, causing the PCM to under-fuel and trip a lean code.
Common cause
Parts:mass air flow sensor
5
Clogged fuel filter
Medium severity
Restricted fuel flow reduces rail pressure under load, leaning out the mixture during acceleration.
Common cause
Parts:fuel filter
6
Exhaust leak upstream of the front oxygen sensor
Low severity
A leak ahead of the sensor draws in outside air, causing the sensor to falsely report a lean condition.
Common cause
Parts:exhaust gasket

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These causes are aggregated from NHTSA owner complaints and general repair knowledge — this is not a diagnosis. P0171 on your car still needs shop confirmation before any repair.

Common symptoms

Check engine light
Rough idle
Hesitation
Surging idle
Poor fuel economy

What to check before replacing parts

Review short- and long-term fuel trims on bank 1

Look for: High positive trims (commonly worse at idle, improving with RPM) mean the computer is adding fuel to compensate for excess air or insufficient fuel — that pattern is this code's fingerprint.

Smoke-test the intake

Look for: Smoke escaping (or a hiss you can hear) at intake boots, gaskets, or vacuum hose connections confirms unmetered air is entering after the MAF sensor, which is the most common cause of a lean code.

Inspect the PCV hoses and valve

Look for: A cracked, split, or disconnected PCV hose, or a PCV valve stuck open, draws in extra unmetered air the same way a vacuum leak does.

Clean and test the MAF sensor

Look for: Visible dirt or oil film on the sensor element, or a grams/second reading that doesn't track expected airflow for RPM, means the MAF is under-reporting air and causing the computer to under-fuel.

Verify fuel pressure

Look for: Pressure below spec (weak pump, clogged filter, failing regulator) starves the engine of fuel and produces the same lean trim pattern as a vacuum leak — rule it out before chasing leaks.

Rather have a pro handle it? Find a vetted local mechanic.

Matching symptoms

Car Runs Rough