2000 Chevy Suburban Fuel to lean

Tiny
BIGDADDYNEILL
  • MEMBER
  • 2000 CHEVROLET SUBURBAN
  • V8
  • 4WD
  • AUTOMATIC
  • 169,000 MILES
My suburban started to sputter then run fine for days, then sputtered and stalled and then ran fine for a few days. Then it sputtered for the last time. I can start it but it will stall. My codes are P0171 and P0174. Any idea what it might be? I changed the Mass Air flow sensor.
Friday, April 17th, 2009 AT 9:01 PM

1 Reply

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
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)
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Saturday, April 18th, 2009 AT 4:59 AM

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