HELP!!!!

[Greg Grimes01]

NEW TAKE ON OLD PROBLEM...

still getting codes p0171-p0174. noticed that when heater is off i do not get the codes.turn the heater on and shortly after the cel comes on. or when i punch it the cel comes on. i guess my next check is the vacuum system for the heater controls. when the cel comes on the heater starts blowing cold. driving me crazy..(very short trip). thanks for any and all help...:smile0001:

 

[Todd Z]

Broken line to Heater control valve under the hood ????



OR bad vacuum switch in dash or line under dash...



Check the valve first... since you heard the sucking noise there....



It is visible from the pass side wheel well next to the serp belt..



If not it is a line some where in the truck..



Todd Z

 

[Greg Grimes01]

thanks todd, i guess its I.T.T (in the truck) checked heater control valve holding vacuum.will try canisters in the morning.. wish me luck.....

)

 

[Kevin Palmer]

Though it is a hassle, it does sound like you at least have isolated it out.

Now a matter of finding it...