Oldsmobile/Buick Repair: buick reatta, buick reatta, vacuum leaks

Question
hey there - having a bit of a problem here. i had a new ignition module put in a year and a half ag, now my mechanic is saying that i need a new one. my car is the 1990 model, always been well maintenanced, has 117 000 miles. my cars check engine light came on after 2 hours of good highway driving and my car began to "chug" as it seemed to shift, this happened between 45-55 mph. when i went slower, it was fine. the next itme was the same, except that after a while i was able to increase my speed and the light went off as well. then i was driving 20-25 mph on another road and the car jsut died on me. now i understand that the car dying COULD be the module, but isnt the chugging something more, like the engine or the transmission? or is the ingnition module the reason for that

Answer
Hi BK,
I have replaced very, very few ignition modules. They are quite dependable.
I would check the EGR valve. If it is dirty, and not seating properly that could happen.
Vacuum leaks also possible, but they wouldn't fix themselves, but the egr could.
Van