I have a frustrating problem I hope one of you can help me with. We have two 1993 Sedan de Villes which we love, but we have a problem with one of them. Sometimes it will shut off while driving, usually while decelerating. The car runs great, has great pickup, great power. But every once in awhile, for no apparent reason, it will simply shut off while driving. Sometimes it will drive fine for two or three weeks, then shut off twice in one day without warning. My daughter primarily drives this car and it is a very scary situation because of course she loses power steering and brakes, and since it usually occurs when she is coasting to a light or slowing down on a curve, she has to react quickly by throwing it into neutral and restarting it (which it easily does every time). The problem is that we have had the car in the shop several times, but the mechanics can't figure out what is wrong with it. They (and three other shops, including the Cadillac dealership) essentially have told us that they cannot reproduce the problem, and until they can, they basically don't know what to fix. We finally just had the shop replace the EGR valve because we had read that this can cause stalling on deceleration, basically just a shot in the dark. My daughter loves this car and can't bear to think of giving it up, but this is very frustrating. The car has 160K miles on it and otherwise runs great. Help!!