Im puting back together intake after a bad headgaket and I noticed underneath my intake manifold there is some kind of sensor about a foot long that is held on by a clip to the underside of the tray. but i dont know what it is or where it plugs into, it looks like it screws into something and then plugs up with the wireing harness but how does it route through?

Thanks for your help - Ryan

The sensor under the plenum is the MAT/ IAT- manifold/intake air temp however you prefer to call it. It just screws into the hole and the two wire weatherpack connector plugs into it. I'm not really certain what your question is?

he may also be talking about the egr temp. diagnostic switch that screws into the base of the egr.

no its not under the plenum its under the manifold or lower intake. once I seal it down the only exit I think is through the hole for the distributer but that cant be right?

ah ok i went to TPI parts and looked at the pics...here it is i believe, it sure looks a lot alike anyway...
It is the EGR, so how does this connect exactly? I tried to go to autozone and entered in 85 trans am but it says EGR is not equiped with this vehicle thing and didnt have directions for it???

85-89 TPI EGR Temperature Switch



Thanks again

it screws into the base of the egr. it is on the top side of the lower intake under the plenum between the fuel rails. i've never heard of any sensor mounted in the lifter valley.

well i guess your right but i coulda sworn i found it under it, but it just didnt make any sense cause its not even oily or nothing so i just wanted to make sure, but mounting on top makes a lot more sense. thnx for ur help

no problem.