how big of an exhaust are yall running? 3" 3.5" or 4" if I do a cutout, I want I will do a manual one, cause I am a poor college student however, I was thinking just a simple 4" bullet,

 

I used a resonated tip with a modified tailpipe to the stock exit on my old STS. The tip should be welded else it does not kill as much noise. My wife hated the extra noise although all I heard was the turbo whine. Sweet, sweet music! The tip was good for a few dB reduction, enough to keep the neighbors happy at 530A and did not kill the turbo whine if any.
Using a muffler w/o a cutout would cause a lot of backpressure and hurt spool time. Increasing the diameter of the pipe would reduce pressure but make it noisier. You can find the tips at most muffler shops and parts stores. A few welds ( about $20 at a decent shop ) will have you on the road fairly cheap.

 

I have been looking at a couple of different options for after the turbo exhaust. As long as you use a straight through type muffler that is as large as the pipe coming off of the turbo it shouldnt restrict it any more than no muffler. The first one I found is made by Aeroturbine wich is a true muffler, the second is also by Aeroturbine but it is a resonator, and the third option is by Spintech which is another muffler.
My goal is to quiet the truck down when I tow. It isnt too loud now but when you put a trailer behind it, it gets loud!

 

you will be 3" coming off the turbo....

 

Well I got my spintech on there and it sounds great. It still has the aftermarket sound, but just a little quieter than no muffler. You can still hear the turbo, but a little less whine. Just a question? How do you tell if your cats are clogged or melted inside? My Egt's were really high for a couple of months and I am afraid that it might have damaged the cats.

 

If your cats are clogged it will run fine until you get on it and then it will feel like something is holding you back.

 

Yes it definatly feels sluggish, not like it used to. It also will not produce boost when the engine is cold.