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1999 GMC C3500 Sierra SL 7.4L Excessive Emissions, Poor Idle Quality, Misfire, Poor Fuel Economy, MIL Lamp on
Posted to GM Driveability on 11/12/2013 9 Replies

Please help with this nightmare. Vehicle back again after we thought we had the problem fixed. Truck runs great when it is cold but after a few days will run consistently poor only when hot. Unrelated to the issue in the last year we have replaced ignition par...

9 Replies Received (View Replies)

  Related Documents & Media  1999 GMC C3500 Sierra SL

 
Message Closed w/FIX

car Vehicle Data

1999 GMC C3500 Sierra SL

VIN 1GDKC34J3X
Engine7.4 L / 8 cyl / GAS
Trans4-speed Automatic (Electronic)
DeliveryFuel Injection
EmissionsOBD-II Compliant
SymptomsExcessive Emissions, Poor Idle Quality, Misfire, Poor Fuel Economy, MIL Lamp On
OccursHot, Idle

Trouble Codes

P0172Fuel System Too Rich (Bank 1)
P0175Fuel System Too Lean (Bank 2)
Message Closed w/FIX

car Vehicle Data

1999 GMC C3500 Sierra SL

VIN 1GDKC34J3X
Engine7.4 L / 8 cyl / GAS
Trans4-speed Automatic (Electronic)
DeliveryFuel Injection
EmissionsOBD-II Compliant
SymptomsExcessive Emissions, Poor Idle Quality, Misfire, Poor Fuel Economy, MIL Lamp On
OccursHot, Idle

Trouble Codes

P0172Fuel System Too Rich (Bank 1)
P0175Fuel System Too Lean (Bank 2)