Engine sputters and loses power while driving. Has stalled while doing this.

While driving, my car will lose power to the point that the RPMs drop into the
100s. sometimes the engine light comes on, but it never stays on long
enough to have the codes checked and the computer won't store the code
which is very annoying. Since I began having this problem, I have replaced
the ICM, rotor, distributor cap, had my manifolds repaired and new gaskets
installed, removed the converter, and will be replacing plugs and wires this
weekend. The rotor and distributor cap were both in very bad shape, but the
plug I removed looked ok. It only has 98,000 miles on it, I love this car, and I
just want to know that it will make it from point A to point B without worrying
about having issues. I do almost all of the repairs myself, my only experience
being on a 91 caprice classic.