I need some tech advice

I have an 01 1.8 t and just to mess around i just unbolted the exhaust from the cat. I was wondering if this does anything harmful but im assuming not because we do it all the time with other imports. I just dont have the lab coat to be able to know everything about audis. There is no CEL or anything smelling bad other than the emmission killing richness. I just cant stop it from resonating and im not sure wether it is the heat sheild, the cat or the free hanging exhaust. I just cant find a place to tie it off yet. Any advice?? thanks

P.S> damn it sounds good with no exhaust at 16psi of boost.