My coolant outlet pipe was leaking so i replaced that along with the temp. sensor and thermostat, and flushed the entire system and refilled with new coolant.

Now is throwing a p0480 and a p0116

At idle it will heat up to operating temp. but when i drive the temp drops to like 150ish

Could th thermostat be bad????

BTW: Its a 2200, 5-speed and i remove the A/C

Any Advise would be helpful

My moms car did this and we have still not figured it out, even took it to 3 different mechanics when I gave up on it and none of them could give us a answer. Hope u figure it out and if u do please post up what the problem is.

It is possible that your thermostat seal, not gasket is not seated properly. I had the same problem, and when I removed the thermostat and looked at the seal, I could see where it was allowing coolant around it.

Replaced the seal and all was good.