KevinS550

I have a 2015 mustang gt thats got a roush phase 1 supercharger kit (dealer install). During the summer it drove fine but now that the weather has dropped to 60 degrees it keeps turning off when put in neutral or in general as I slow down to a stop. For example i'll start the car in the morning and let it fully warm up. Then when I take it out and come to a stop sign or light, I would toss it in neutral and the rpms drop and the car shuts off. Even if I down shift and keep the clutch in it will still turn off. Even in the summer on a cold morning after I let it warm up it tended to do the same. With only just under 4,000 miles it seems strange. It has kooks headers and I tend to get a P0420 code but I doubt that has to do with it as it only happens when its cold out. It has the mandatory roush tune and that's all. Other then the P0420 code I got a misfire a while back. Pulled off the road turned the car off and back on and it went away. That was 4 months ago and havent had it come back on. 93 pump gas always. And always starts up with zero hesitation. Any ideas as to what it could be?

TheReaper

It sounds like it could be an issue with your tune.