Code P0171 - System Too Lean The OBDII trouble code P0171 - System Too Lean (Bank 1) means that the engine air-fuel mixture is too lean, or there is too much air and too little fuel. Driving a car with the code P0171 can cause more damage to your vehicle over time, as when the engine runs lean, the combustion temperature is much higher. • Symptoms • Causes • Diagnostic • What is a vacuum or intake leak? • Common problems causing the code P0171 • Basic car knowlege: how the air/fuel ratio is adjusted • Long and Short fuel trims • What do terms Bank 1 and Bank 2 mean? Symptoms: Typical symptoms of the lean air fuel mixture include: - Lack of power - Rough idle - Hissing noise from the engine (vacuum leaks) - Stalling - Difficulty starting - Engine knock or detonation (pinging) under load - Engine running hot Causes: Common causes include: - Intake or vacuum leaks - Clogged or faulty Mass Air Flow sensor (MAF) - Faulty PCV valve - Stuck open purge valve/ solenoid - Faulty oxygen sensor - Improperly installed aftermarket cold intake - Low fuel pressure - Clogged catalytic converter
Posted on: Sat, 17 Jan 2015 06:00:33 +0000