[Chris89]

I've got an 89 na supra and i was thinking about gutting the cat and running a 2.5inch pipe through it. What are the pros and cons in doing this? My cat-back is welded to the cat, so i was gonna unbolt the cat from the manifold and saw the pipe off the cat-back end. Then gut it and weld a 2.5 inch pipe through it, then rebolt to manifold and use Exhaust clamps to connect the cat-back to the cat.

 

[figgie]

gutting the cat will create a plenum. It is better to put a test pipe in than have that chamber

 

[Chris89]

That's basically what i'm doing. gutting all the honey comb crap out and sticking a 2.5 inch pipe through the cat. So it'll be completely free-flowing.

 

[Zi4life978]

probably won't notice much... maybe exhaust might be a little throatier? Maybe it would be better to get a high flow cat instead of a test pipe for some back pressure, and it'll be healier for the environment