Hi, I have an 87 camaro , and I was searching for help determining if I have a possible catalytic converter problem. The other day the car started running rougher, a more puttering sound that reminds me of a motorcycle or motorboat when I press on the accelerator. There is less acceleration, and definitely within the 40-45-50 mph range it really struggles to accelerate and the car vibrates a bit. There is also a weird smell I notice during this. I had thought replacing my bad vacuum hoses would improve the problem but it didn't. I haven't tested the catalytic converter yet but does it sound like that could be the problem? Also what's the cheapest one I could find should I need to replace it? I appreciate any help, thanks

 

First, you need to eliminate the possibility that it's a fuel or ignition problem.

 

I discovered that I had a loose spark plug wire, hanging down and sparking against something