i have a mac cat back on mine..they sound good, but honestly..i donno if its just mine, but all the connections throughout the exhaust are rusting out bad, some even have rust holes in them, it sounds good for a v6 i guess, i was happy with it, until today actually..i took it off to straighten it, again i donno if its mine but it sags bad, they tail pipes line up good and dont sag, fit right up under the bumper, but yea they seem to be rusting out bad...OH as well as one of the baffles inside the muffler broke loose in side the muffler, and i turned it upside down while and i had to pull it out, so all in all, i was happy with the sound, but rather its just mine or not...quality wise, its not holding up to well...iv had it a year with it on, rather or not how long the previous owner had it on there i donno...and for what i know just looking at the system i have...ud have to get an hpipe/xpipe to get true duals, to get rid of the cats, because the cats y into one which y back into two going to the duals