So.. i have a zzp short header, and 3inch downpipe with higflow cat, running into a full 2.5 magnaflow cat back exhaust.

We can not get any of it to properly without it rubbing. It rubs near the top of the rear axel, and also rubs rate on the highflow cat on the side wall.


we have tried adjusting ot make it no rub, all i get is rattle goign down the road.. any ideas on how i can get rid of the rattle,

 

It's likely a problem with the cat back flange...is the downpipe designed to mate from 3" to 2.5"? As well you shouldn't have problems with the magnaflow not fitting it's a slip fit clamped exhaust.