Car stalls when I put gas in

Are you saying that as you are filling your car it stalls? If so, your car will probably run rough with the gas filler open,please dont run your car as you fill it.

Just a word of caution - never *top off* fuel tank when re-fueling - doing so may force raw fuel into the emissions (EVAP) system and temporality flood engine upon restart after filling tank. Vehicle is under warranty - recommend having *GM dealer* investigate / evaluate this concern - @ no cost to you!