Now that the summer months are here and it's up near 100* here in Dallas, my car is starting to have issues with running too hot.

I have about a 45 minute drive from work to home. The car runs at a normal temp (the 180*-ish tick on the gauge) all the way until I get about a mile from my destination and get stopped up in traffic. Once I'm in it for about 5 minutes or so, the needle on the temp gauge goes up to the 210* mark on the gauge and you can tell the computer clicks over into safe mode or something... starts to idle down, the ac clicks off, will barely accelerate at all once you start trying to drive again, feels like the trans keeps shifting all around... All until I get rolling again and the temp drops below 210* and it drives like normal again until I have to stop again.

The car has had a 160* thermostat in it for probably 10 years now, mostly water with the coolant and 2 bottles of Water Wetter. It's never had a problem until recently.

Also I have a DHP reprogrammed computer I bought from the grandprixstore a couple years ago. I was wondering if the tune wasn't set up for the 160* thermostat if it would cause the car not to cool properly?