yea im running a cat and no the car doesnt over heat at all it does pretty damn good lol i drove it from zephyrhills without a glitch besides the white smoke that went away after driving it a while but it still does it and i have a camaro under a tarp and when i reved up the SI to capture what it does on video i looked at the tarp and it had what it looked like oil splash from the exhaust but no black smoke or blue smoke just white smoke and that ??