Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSCHEVROLET1997CHEVY EXPRESS G3500, VAN CARGO, 6.5 FREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 33 (ENGINE CONTROLS - TESTS W/CODES - 3.8L)TROUBLE CODE CHARTSCODE P0171, FUEL TRIM LEANDIAGNOSTIC AIDS

1997 Chevrolet Chevy Express G3500, Van Cargo, 6.5 F

Diagnostic Aids

1997 Chevrolet Chevy Express G3500, Van Cargo, 6.5 FSECTION Diagnostic Aids

WARNING: This page is about a different car, the 1995 Pontiac Trans Sport, 1995 Oldsmobile Silhouette, and 1995 Chevrolet Lumina APV. However, it is still accessible from the selected car via links, so may be relevant.

If problem can not be isolated using diagnostic charts, monitor LT fuel trim and fuel trim cell while operating vehicle under various loads. This may isolate condition which caused Code P0171 to set.

Fig 1: Code P0171 Schematic (3.8L FWD Van) Fuel Trim Lean

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.