GT starts fine, but stalls when at stop sign or light.
 

Whats going on everyone..



I have a 03 GT 4.6 Auto and I'm having an issue. My car starts fine, however when it seems to warm up it'll cut off. Yesterday I was driving it to Autozone to get my codes read and it drove perfectly. As I approached a stop sign and slowed down, the car would stall and die. Sometimes it'll crank right back up, other times I'll have to wait about 10 mins before it'll start back. I finally got to autozone and pulled the codes. It said P0125, basically a thermostat.. I replaced my thermostat about 5 months ago but maybe its stuck open. Would that cause the car to stall only when im idling at a light or stop sign?



Going a little deeper that day, I bled my coolant with that funnel kit. I've also cleaned my IAC, but no change. I purchased a new one, and still no change (took it back). Next I'm about to clean the MAF sensor and possibly the EGR to see if anything changes. I thought it may have been a blown head gasket but I didn't want to jump to the worst conclusion. I noticed that vanilla milky pudding under my oil cap, but that doesnt necessarily mean its that. It wasn't on my valves though, just underneath the capside.



If anyone could help that would be outstanding.



Thanks..

do you have the ability to monitor ECT while driving the car?

Stalling when coming to a stop can be a sign of a sticking EGR valve. Could also be fuel. You could also rent a block tester from autozone and check and see if your head gasket is blown.