My 2000 mustang is stalling alot when i m stoped at a light. I dont know why this is happening. it happened after i put on my O/R xpipe coulde this be a problem? need help

 

Mine did that to but not due to an exhaust upgrade. I cleaned the air idle control valve with carb cleaner, in and out. When that didnt wotk I replaced the throttle position sensor, and that worked.

 

It wouldnt have to do with exhaust. I've always replaced my IAC when it stuck open, because chances are when you clean them they stick again. ( i had a come back at my dealership, so i dont take chances anymore.)