Join Now
International Automotive Technicians Network

P0171 Diagnostic Trouble Code Discussion for August 2014

Fuel System Lean (Bank 1)


Note: This is a professional automotive technician's resource.
Vehicle Owners: If you are seeking an automotive repair professional to service your vehicle, visit the iATN Repair Shop Finder.

Trouble Ticket Help Requests for DTC P0171
Help Request Posted
1996 Chevrolet Cavalier 2.2L Excessive Emissions, Poor Idle Quality, Hesitation, MIL Lamp on VIN: 3G1JC1247T
P0171: Fuel System Lean (Bank 1). ... great vacuum idles fine. Once in closed-loop the vacuum slowly drops from 18in/hg - 8in/hg and eventually stalls out. I see this happening on the scan tool and actual vacuum gauge. If I unplug the O2 sensor or tsp to force it back to open loop, the vacuum ...
August 01, 2014
1996 Chevrolet Cavalier 2.2L Excessive Emissions, Poor Idle Quality, Hesitation, MIL Lamp on VIN: 3G1JC1247T
P0171: Fuel System Lean (Bank 1). ... great vacuum idles fine. Once in closed-loop the vacuum slowly drops from 18in/hg - 8in/hg and eventually stalls out. I see this happening on the scan tool and actual vacuum gauge. If I unplug the O2 sensor or tsp to force it back to open loop, the vacuum ...
August 02, 2014
2000 Chevrolet Express 1500 5.7L Hesitation, MIL Lamp on VIN: 1GBFG15R8Y
P0171: Fuel Trim System Lean (Bank 1). When first started cold...will pop and sputter. Took on road test with fuel pressure gauge hooked up at full throttle will pop and back fire thru intake...fuel pressure will go to 61 psi and stay there until throttle released, then it will jump down to 52psi. ...
August 04, 2014
2000 Chevrolet Express 1500 5.7L Hesitation, MIL Lamp on VIN: 1GBFG15R8Y
P0171: Fuel Trim System Lean (Bank 1). When first started cold...will pop and sputter. Took on road test with fuel pressure gauge hooked up at full throttle will pop and back fire thru intake...fuel pressure will go to 61 psi and stay there until throttle released, then it will jump down to 52psi. ...
August 05, 2014
2008 Audi A4 Cabriolet 2.0L Poor Idle Quality, Misfire, MIL Lamp on VIN: WAUAF48H98
car runs perfect when cold and under load. Live data short term fuel trims within spec when running good, seems to be once warmed up short term fuel trim goes all the way to lean 25. with no obvious vacuum leaks. At that point also car will begin to misfire. I...
August 06, 2014
2007 Volkswagen Passat 2.0T 2.0L MIL Lamp on VIN: WVWAK73C47
P0171: . ... a/c compressor, and vacuum pump. Vehicle already had check engine light on for P0171. Performed services and smoke tested. Found no vacuum leaks. Checked MAF readings and they are reading correctly, even swapped in a new MAF just in case. Additive fuel tri...
August 28, 2014