exhaust leak

[michael]

I think I made a big mistake, About a year ago I installed a stebro cat back then a few months later I started to get a rattle from my cat. I thought (don't say thats my first problem) the engine would run more efficently with a new set of cat-less downpipes, turns out not. anyway now I have a leak from my manifold to downpipe that blows it's gasket every 3 mo. If anybody has any suggestions about increasing my lost backpressure and a part # for the gasket I'd appreciate any help. Thanx.