i am thinking of doing away with the muffler on my 06 6 speed and just running a straight pipe. anyone ever tried it?

It won't really sound all that different if you leave the Cat on there. I have rode in a truck that is that way, and it makes a little difference, but not much. Loose the kitty, and you will notice more. And, your performance will be greater as well.

Moved to proper location. Please make sure you are posting in the correct forum. Thanks

does it void the warrenty to remove the kats, the truck is approx. three months old and i really do not want to void the warrenty

Yes, it can. It all depends on the dealer. Most dont even know that they had one to begin with though.

Bud, trash the muffler and buy a cat delete pipe (make sure you keep the cat for stealer and emission visits). You'll love it! In my honest opinion, don't bother with a 4" system. Doing the above will do just about the same for a lot less. If you don't think you'll ever have to worry about the cat, then buy one of those cheap 4'' strait pipe kits off of EBay; can't beat the price.