i've had my 2.5" system on my car for a while now. but i have one problem that i have since wanted to rectify after putting my new headers on. the flange from the cat and the flange of the exhaust are at 2 different angles. i first thought it was a gasket. however after changing it and seeing that it was still making the same rattly noise i noticed where the gasket was tight at the top. it had about a millimeter gap at the bottom (toward the ground). whats the best way to sort this out?
cheers guys.

Exhaust shop

if thats the case. any idea of cost?...

The bloke i go to probably wouldnt charge any more than 20 bucks. Less than an hours work when ya know what your doing. Which i really dont.