I had the same problem in my 4 banger. I would be highway driving (70mph) and when I had to slow down to pay a toll the car would shut off. My problem was dirty fuel filter. Then I a few weeks later I had a bad 02 sensor (bank 1).
"Do what you like, Because you have to drive it!"-Me
99 Contour LX
95 Mustang GT Convertible
97 Z24 Cavalier