How does that set up sound? And what would work better? 2.25" from the manifold to the cat then 2.5" the rest of the way back, or 2.5" all the way to the muffler and 2.25" tail pipe?

i wish i could get that kind of mileage on mine. i only have 31s and 3.55 gears with my auto and hte gas mileage dropped alot. i don't have any armor or roof racks and i have stock bumpers. my jeep is stock, minus the lift and the 31s. yes, the jeep is a box but its not geared or even designed for gas mileage. its designed for 4x4 and being the best suv back in its time, which is when gas mileage was not on people's minds.

zeep99xj, mine sounds good for what it is, nice and throaty but not too loud or obnoxious. the setup you said is what is on mine at the moment, but i have plans to switch to a modified HO manifold and go 2.5 manifold-to-cat-to-muffler and use a 2.25 tailpipe. keep in mind that as the exhaust gets further from the engine it cools. when it cools, it contracts and needs a smaller pipe to help maintain velocity. that is why it is suggested to use one size smaller on the tailpipe.

zedpapa

This thread got big quick and off topic in some areas. haha. I dumped my exhaust before the axle and dang does it rumble inside and out, i really only wanted it loud out, gonna have to run the pipe out the back. Its hard to get a 3 inch tip back there though since i have really long shackles