I have a 2000 disco 2 previous owner has already removed the resonator from the rear. I'm wanting to remove the center muffler from it now. It can be heard now but I'd just like to make it a little louder.. my question is if I cut out the muffler and just replace it with a pipe will it cause problem with the down stream sensors after the cats. Btw I'm leaving the cats alone don't want it so loud i can't hear my self think... any help or suggestions?

 

I straight piped my center reasonator (or the suitcase muffler) but left the rear muffler. It's loud, like my son hears me coming down the street. Neighbor with a tuned 500hp M3 with full exhaust mods (no cats, 1 reasonator, hears me coming from 2 blocks away.

Cold start is loud, then it quiets down a bit, but think about going near the throttle, and it will wake up the the neighborhood.
With no mufflers or reasonators, its gonna be extremely loud.

It will not cause problems with the O2 sensors. Mufflers are for noise and back-pressure.

 

Pretty much what dgi said. These are really loud engines. A good sound no doubt, but id be willing to bet you'll be putting a rear resonator back on at least. I ran straight pipes after the cats on two separate occasions. Once, my exhaust just sorta fell apart. The second time was on purpose and the drone was insane. Just so much noise inside the truck.