1995 Oldsmobile 88 pass key 2 codes

I bought this olds for nearly nothing from a fellow tech, he was given the car by a wealthy couple to fix and give a needy family. He soon found out he didn't want to put any more money in it with the economy like it is. So I think, i'll give his parts money back and my wife can drive it.
it was giving cam sensor and crank sensor codes, so I change both, and I notice water pump was leaking onto the crank sensor. I think, I got it I put all ac delco parts. The same problem I change pcm, it runs good but the light comes on I scan it, pass key 2 codes, security system codes that were not there before, it still ran 2 days then no start I cleared it, and left key on ten minuitesto reset the security system I guess factory then it ran agian. WHAT DO I DO NOW? Please help me before I burn this very nice car.