I would just do the sanity check first before replacing anything. 30 seems hot to me, but I don't know that engine type.
Leave the car overnight. Next morning plug in your scan tool, and BEFORE YOU START THE ENGINE watch the Coolant and IAT temperatures. If both are giving similar and sensible readings (I would guess circa 10 degC outside at the moment), start the car. Continue watching both. Coolant should rise to 80-90, and IAT may rise a little - depends how much effect the throttle body heating has. If the IAT stays at 30 all the time, then it's probably goosed.
I would not just go around replacing things willy-nilly, if for no other reason that 20 year old plastic connectors that have never previously been disturbed can and will break as you wrestle to get the wretched things apart. And then you will have to replace something, even if it wasn't broken in the first place.