i plumbed a t into my heater core line to run a t-stat sensor for my e-fans would this act as a restriction and keep my truck from running cool?

 

No, but which one did you put it in? And I don't think that's the best place to put it as far as the fan is concerned.

 

i put the T in the heater core line going fron the intake to the heater core. I was thinking about removing the T totally and just relying onthe toggle switch, leaving it on all the time. also could an o2 sensor make my truck run hot?

 

Where you put the T is in the coolest line possible. I don't have an E fan, but I thought most setups, stick the thing in the fins of the radiator

 

Only if it's failed in such a way that the PCM is dialing the mixture to a severely lean condition. You'd probably notice it, as it'd ping like a box of BB's dumped into a bathtub.

 

it kinda hesitates off the line like its starving for fuel. i thought the heater hose intake line was a good place. also it idles at 200.

 

That is the return line, not the supply. It will be cooler and not be accurate. BTW, Have we talked about 35" tires with 3:55 gears and the plenum? LOL

 

aps plenum kit installed - which is the heater hose intake line? what would cause my truck to run this hot?

 

Whats up with his custom tunes? Interested.

 

hes got a sct tuner im looking into buying