2005 impala heating up

[mmmshiny]

alright lately since i drove down from michigan to florida my car is running a bit warmer than usual. i had the intake gasket replaced before i had left michigan. now it is running up near 200 during idle, or stop and go. as soon as im driving it cools back down near normal level. i had a friend who told me it may be the thermestat is sticking. i had a cooling system check done at the dealership. everything appeared to be fine. anyone have any ideas what it could be? also, i know i may need a new cat if that would have anything to do with it. oh and one more question. would it mess up my air flow sensors if i hollowed out my cat or put on a straight pipe? its a 2005 3.4

[Gems]

The standard thermostat opens at 195 degrees... So it sounds normal to me...

[NocturnalCreations]

It could be ur coolant mixture. We adjust our antifreeze mixture for our retarded climate in Michigan. Like -20 to 100 degrees. You might need to make a simple adjustment for warmer weather. Not sure on the %, just a thought. Elevation will also effect a vehicles performance. So if ur in the mountains ur car needs to be re-tuned for that elevation.

I cut the cat off my 95 3.1 and put on a straight pipe to compensate my port job on the heads. Seeing that u have a 2005, u probably have a billion more sensors than I do so im not too sure about it. But I would do it if I needed to do it, not just for the hell of it.