I just bought a 91' Camaro RS. The car ran perfect for about the first month. Then I had to replace the starter. Right after that, the car would sputter and RPM would jump really bad when idling. Few days after that it wouldn't start at all. A friend of mine did a diagnostics and came up with two codes. One for the throttle body (which i replaced and still didn't work) and one for something in the ignition. We put a new ignition switch on it plus new spark plugs, new wires, new rotor, new cap. Also did fuel injection cleaner and now it will start and run for about five minutes, then die again. Also, there is an awful smell and the exhaust is running really rich, black. I know the smell may be the O2 sensors which I am going to change this week, but i don't see that fixing the issue. I know my catilytic converter is clogged which i am going to change out this week also, but do you know that could be causing it or have any other ideas? Thanks for much for any help.