2003 Chevy Tahoe Idle stumble. Codes P0101, P0171, P0174

BEOWULF94

MEMBER
2003 CHEVROLET TAHOE
V8
4WD
AUTOMATIC
75,000 MILES

My Tahoe has a rough Idle quite a bit. It is not all the time, but the MIL comes on a lot with the lean codes P0171 and P0174. I recently got a new code of P0101 in addition to the others. I'm thinking the MAF? However, I have cleaned it with a can of MAF cleaner spray. Didnt help. Also, I cleaned the throttle plate of any crud. So I dont think it is sticking. Do you think I have a vacuum leak? I dont want to start replacing perfectly good parts. Any ideas? What seems to be the most common reason for this in 2003 Tahoes? Thanks for any help here.

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

P0101. Mass or Volume Air Flow Circuit Range/Performance Problem.

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)