Hey guys, I just thought I would add my .02 about adding an exhuast system. I recently added a cat-back MBRP to my LLY and I cannot hear any changes in the exhuast sound unless I am really listening for it. I'm 26 years old so I am not going deaf (just yet) either. I thought this might help those who are worried about thier truck getting too loud. I know I was. Hope this helps out someone.

Thanks for the feedback. I'm going back and forth between the TTS and MBRP. That does help w/my descision since it seems like it's easier to find a good deal on the MBRP.

Had mine done last week with 5 inch tip but did it turboback. I can tell a difference. When I fire it up there is definitely a short and airy pop. Sort of a wheezing/whirling sound at idle (turbo). Was in interstate this morning when a Ford came upon me at 70 mph and I can assure you that he heard a difference when it was on....guttier sound on acceleration.

Let's put it this way: I haven't turned on my stereo since I put the exhaust on. :ro)

I think the it is safe to conclude that leaving the cat on does make a difference in quieting the sound. To me sounding good means being quiet. To others, sounding good means loud. Also, I can't help but to think that some of the folks that have complained about the MBRP being loud may have installed the muffler backwards, because mine isn't loud. If it ends up getting louder with time, I can always got back and add a resonator.