Mechanics

0171 AND 0174 CODES

2007 GMC C1500

Engine Performance problem
2007 GMC C1500 V8 Four Wheel Drive Automatic 42000 miles

Ok, I've searched the boards and can't seem to find a solution. My 2007 GMC 5.3 truck will not start the first crank (about 5 seconds) and starts great on the second try. The truck seems to run fine once it is fire up. I am not having the idle problems or stalling as some of the other posters have had. Any help?
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Rudy99
July 14, 2009.



2007 GMC C1500 0171 and 0174 Codes

P0171/P0174

A lean fuel condition can be caused by: * Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (Use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (Try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)

Rasmataz
Jul 14, 2009.