Quote Originally Posted by MetroMPG View Post
Welcome to the forum, Yellow09LT!

Thanks for posting the info on the Sonic t-stat housing fitting the '09. Nice find.
I was just about to update the post. The newer thermostat and sensors run cooler; the computer does not like that. It activated the check engine light with a thermostat/ temperature fault. Detailed message stated that coolant temperature was lower than normal. My plan is to swap in my old temperature sensor, see if that works. If not, I'll put on the thermostat/ sensor I bought originally. I'll update again with what works out.