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1999 Chevrolet K3500 7.4L MIL Lamp on
Posted to GM Driveability on 9/3/2003 9 Replies

Good day to you all,

After replacing the thermostat on this truck, the fuel trims were still out of range. Further checking lead me to pull the PCV valve so that it was breathing fresh air. This caused the LTFT and STFT to immediately fall into normal range. ...

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  Related Documents & Media  1999 Chevrolet K3500

 
Message Closed w/Summary

car Vehicle Data

1999 Chevrolet K3500

VIN 1GCHK33J3X
Engine7.4 L / 8 cyl / GAS
Trans4-speed Automatic (Electronic)
DeliveryFI / SEFI
EmissionsOBD-II Compliant
SymptomsMIL Lamp On
OccursAlways

Trouble Codes

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

car Vehicle Data

1999 Chevrolet K3500

VIN 1GCHK33J3X
Engine7.4 L / 8 cyl / GAS
Trans4-speed Automatic (Electronic)
DeliveryFI / SEFI
EmissionsOBD-II Compliant
SymptomsMIL Lamp On
OccursAlways

Trouble Codes

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