Hello! My first post here and new to modding etc so bare with me!
I have a completely standard xr6 non turbo, 196k on the clock. I'm thinking about getting a cat back exhaust system and I'm not sure if it is worth it. Do I need to work on the induction side of things first? Or will a cat back make a difference without any disadvantages? I also assume it will make nice noises

Cheers

It will (should) make nice noises. But. Without headers (extractors) and a high flow cat, do not expect large gains as thats where most power can be made in the exhaust. As for the intake, doing that as well will give you a little better economy, better induction sound and make it easier for the engine to breathe and give you a touch more power.

On my BA, I've used a Territory intake pipe (no big dent over the manifold - straight unobstructed flow. You will need the spacers off the territory to clear manifold. It will rub on bonnet lining), a turbo/v8 snorkel (much wider intake area) and I also have a Hyperflow. Which is basically a metal version of the Typhoon lower snorkel. It sits in the high pressure area behind the head light. The lower snorkel is just fitted to the standard air box after you cut the hole out.

My exhaust consists of; Pacemaker 4490's, Venom High flow cat, Redback 2.5" cat back. Sound clips are plentiful on youtube to help you decide.