about 2 weeks after I got my xr6 (03, 75,000km) , I was driving it home from work, was about 4 mins into the trip and all of a sudden lost all power, got the massive engine shakes, and sounded reeeaaallly crook.. and engine light on etc.. left it for a little bit, started it up and went fine, drove it home, and happened again on way home.. (total trip home from work is about 15 mins) .. parked it up .. straight to ford in the morning and they changed out the TPS .. apparently it was faulty.. and its never happened again since. kinda like your problem, but I never had engine cut out..