P0117 code/ ECT sensor location

Short question: Where's the ECT sensor located?

Background:
After picking up my Tacoma from the body shop yesterday (front end damaged in a collision), I noticed my temp gauge was pegged at "H" driving home; I made a beeline for the nearest parking lot and just as I pulled into the parking lot the temp started going down after the CEL was thrown. The gauge went back down to the normal position and I limped back home...nothing sounded/felt out of the ordinary. I did notice that after getting back home the engine sounded a bit "weaker" while starting it. I didn't have my scangauge with the truck as it was in the body shop for almost a month.

Got home, ran my scangauge, and a P0117 code was thrown. Checked coolant level and it was way low. W.elnt to Walmart and got some Prestone 50/50. Noticed some coolant where it should NOT be, namely at the bottom of the skid plate and the back of the front bumper I've filed up the reservoir and it's been at a steady "FULL" ever since last night.

Today, while driving around the engine seems to take longer to warm up from a cold state than before (driving to work is 2 miles and I know how warm the engine is by the time I get there since it hasn't reached normal operating temperatures). But after 10-15 minutes of driving the scangauge starts showing temps of 204F and higher.

Another thing that's happening is that after starting the truck after it's had a short period of time to cool off (after shopping, for example) the temp will keep going down WHILE driving (say 165F down to 159F) and then start going up, and like before as I keep on driving (around town I haven't tried the highway yet) it'll keep on going up past 200F.

Since the coolant overflow tank is still full it might be the ECT sensor; I've looked around online and can't find any sources showing where it is. Anyone here know where's it's located?