I have a 99 mustang cobra, I can take off sometimes and it kinda stutters. I just had both head gaskets replaced along with every other gasket in the car! Got the car back an I can be driving 10 mph, 50 mph, getting in it or putting along and it just dies. The speedometer needle will fall and pick back up when it wants to and the odometer will read straight lines. It doesnt do it all the time but it will happen maybe once in a day and maybe thirty times a day. It has a mind of its own! It will start back up right away sometimes and other times it may take ten or fifteen mins to start back. I hit a water hole one day and the speedometer and odometer stopped working but after two days i guess dried out and started working again. Im really confused about this problem. plz help
