He seems to be asking where the IAC (Idle Air Control) valve is at, not the IAT (Intake Air Temp.).
The IAC is one of those 3 sensors on your TB. It looks like this and is held on with 2 bolts...
I wouldn't replace the TB screen, but just clean the entire TB w/ the appropriate cleaner (not carb or brake cleaner) and call it done. The butterfly in the TB gets gummed up after years and sticks sometimes. Also clean the passages for the IAC, etc... Get a new TB to UIM gasket as well or you will have leaks.
