mjr46

if car is overheating at idle check to see if elec fan comes on...most likely it's a cooling fan issue

kennebellgt

inside the radiator looks good, and my fan seems to be just fine, and YES i bought the car with two and a quarter inch piping and its a xipie with stock cats.

89stang0890

replace the cats

xfasteddiex

to check cats put it on a lift with a welding tip on torch blow a small hole 1/8-1/4 "inpipe infront& rear of cats startcar & check pressurs in front & behind catsit shouls be nearly equil mabe a bit more in front if a lot more in front replace them if not weld up holes i worked at amufflershop for a few years & ive done many this way

badtzmaru

A couple of questions: your mods that are on your list, did you just do them not too long ago? did it happen (overheating) after mods? the reason I am asking is because when i started modding my 94GT it started overheating while at stop or reduced speeds but as soon as I step on the gas and started moving it started to cool down, i checked radiator, fan and no problems so what i did to resolve this was to change the thermostat (lower temp) and so far no problems.
Anyway, good luck.

cody91mustanglx

the cats are worthless, unless u live in california, but if ya dont, u need to remove them and go with a off road x pipe