So my t-stat has been stuck open, so FE has dropped...
I took a freeze frame when the code hit (shown below). This was after 15 minutes of highway driving. Exterior temps were around 55°F. As you can see, the engine temp is 150.8°F:
The CEL has popped on twice in the last month with this code. Fuel efficiency has been pretty decent but not great. I typically drive 65-70 in a 55 and 75-80 in a 65 as that's the flow of traffic. If you do any slower around here you'll be run off the road, usually by a large truck:
I picked up a t-stat and need to replace it ASAP. I really want to do a grille block, maybe even this Saturday if the weather allows. At least that will get the temps back up.