Having problems with your 1999 Chevrolet Express ?

P0171 AND P0174B WHAT DOES IT MEAN?

\015 DTC PO171 AND P0174B NOT ENGINE PROBLEMS YET BUT WHAT SHOULD I DO?\015 Posted / edited by AnonymousUser on : 19-11-2018

Answers :

Trouble Code: P0171

Fuel Trim System Lean (Bank 1)

Possible Causes:


Air leaks in intake manifold, exhaust pipes or exhaust manifold.Fuel control sensor is out of calibration (ECT, IAT or MAF.)Low fuel pressure (fuel filter clogged, pressure regulator failure).One or more injectors restricted or pressure regulator has failed.HO2S element is contaminated, deteriorated or has failed.Vacuum hose is disconnected, broken, leaking or loose.Trouble Code: P0174

Fuel Trim System Lean (Bank 2)

Possible Causes:


Air leaks in intake manifold, exhaust pipes or exhaust manifold.Fuel control sensor is out of calibration (ECT, IAT or MAF).Low fuel pressure (fuel filter clogged, pressure regulator failure).One or more injectors restricted or pressure regulator has failed.HO2S element is contaminated, deteriorated or has failed.Vacuum hose is disconnected, broken, leaking or loose.

Repair Help & Product Troubleshooting for 1999 Chevrolet Express

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