This is what I found on a post on the forums.
either gut, or leave the cat alone, both are fine, for sure leave the resonator alone, and change the mufflers, since this is the part that muffles the sound, by changing the mufflers only, your changing the exhaust tone.
This guy wanted to delete his cat. It was also said that if all your looking to do is cahange the sound, is to change the mufflers along with the u-bend. Hope this helps with some ideas to get you going in the right direction.