yes, they go to the iac.
Idle Air Control valve on the throttle body.
in doing this job, i've read that the coolant is drained. why? are there coolant hoses going through the plenum, throttle body, etc?
don't even touch the cooling system.... just undo the 4 bolts that hold the throttle body on and set it aside. I have NEVER had a issue with reusing the throttle body gasket (just don't even touch it!) on ANYTHING. If it makes you feel better you could probably get one. DO replace the intake manifold gaskets... and don't forget the upper manifold splits apart and uses the same exact gasket for both halves.
also you can leave a few things connected on the manifold and just flop it out of the way...
Assuming this is a V6 anyway.
edit: in all fairness I do usually reuse the intake manifold gaskets unless they're paper. the rubber ones are usually OK to use again. never had an issue. 5vz uses metal gaskets.
don't even touch the cooling system.... just undo the 4 bolts that hold the throttle body on and set it aside. I have NEVER had a issue with reusing the throttle body gasket (just don't even touch it!) on ANYTHING. If it makes you feel better you could probably get one. DO replace the intake manifold gaskets... and don't forget the upper manifold splits apart and uses the same exact gasket for both halves.
also you can leave a few things connected on the manifold and just flop it out of the way...
Assuming this is a V6 anyway.
edit: in all fairness I do usually reuse the intake manifold gaskets unless they're paper. the rubber ones are usually OK to use again. never had an issue. 5vz uses metal gaskets.