is putting a cat back system on my 92 good or will it not make any difference in the sound/performance??

 

That depends on what you have now, and what you plan to replace it with.

I'll assume you have the stock exhaust system - yes, it would make a difference in sound. Almost all the aftermarket exhaust systems out there have their own 'signature' sound... Flowmaster, Hooker, SLP, Edelbrock, and others. They all sound different, they all vary in sound level.

As for performance, there may be some gain, but if you still have the factory Y-pipe, exhaust manifolds, and cat converter, then you'll have left the biggest bottlenecks in the system, so the gains will be little to none.

With headers and aftermarket/custom Y-pipe, the gains can be pretty big. Everyone knows the stock manifolds and Y-pipe are pretty sad, but most don't realize just HOW bad they are untill you change the entire exhaust system out for a real performance exhaust system (notice I said 'exhaust system' and not just 'headers' or 'catback')