hi my 323 1998 is losing acceleration feels like a clog in filters the revs were going up & down when idiling and last week it died with batt light coming on, was told i needed a new alternator which i got and now the revs are staying at about 800 when idiling,however it has not stopped the accelleration loss, i have replaced the plugs and filters anyone any ideas,is it a job i could do myself, i hope so as ive just replaced the alternator and one of thr rear shockers which wasnt cheap, thank you

 

It couold be a number of things, as you have obviously already guessed.
How many miles?
My wife's Saturn recently hada similarproblem w/<130,000 miles on it and it turned out the catalytic converter was bad. Her car got so bad that it was nearly undriveable. You either had to be completely on or off the gas and w/that acceleration was that of a loaded 18-wheeler. Mileage too.
Has your mileage dropped?

 

thanks, it has >120,000 miles on the clock another thing it sounds as if its only firing on 3 cylinders..

 

Well then, start pulling plugs wires.The one that makes no difference in the way it runs it the trouble. You"ll have to take it from there... either bad plug or wire, or a bad dist cap/rotor or coil.
If it helps any, my wife"s car started sounding louder inside the cabin, kind of like it was straining to provide the power called upon it when the cat was going bad.