that plug def goes to one of the vsv's under the intake
as for your temp issues... there are two temp senders located on the thermostat housing, one is a two pin plug and usually green or grey depending on year.. that one is your ecu temp, the other one is just a single spade terminal (and if it's old) where the spade terminals comes out the sender will be a reddish colour and breaking into smallish pieces thats your dash gauge
well... here's a grayscale one lol
http://www.rockauto.com/ref/SMP/SMPD....html?TS73.jpg