I had my tranny rebuild on my 1989 525i with m20 and 4hp22 transmision at AAMCO. The guy just called me and says tranny is in but the engine now sputters, doesn't idle well at all, stalls. Now they can't start it. They say I need a new cat converter?? The car was running great until I lost forward gears and the cat was not showing any signs of dying.
What did they do?? Please help.