ok see if any of yawl can give me answers.
i have a 04.5 lly duramax. i have the banks 4 inch exhaust on it. i was wondering what i can do to make it louder than what it is. because i go onto youtube and there are lly's on there that sound nasty. so i was wondering if anyone out there could tell me how to make mine sound nasty and NOT BE QUIET..
ive also been thinking about taking the cat off of it also. but i cant find a cat delete pipe. any ideas??

 

MBRP for a cat delete, and straight pipe to delete the muffler. That'll give you some noise.

 

MBRP and a few others sel the full turbo back (actually its a downpipe back) system. Removing the cat and muffler will make it plenty loud behind you. I had the MBRP downpipe back kit with Cat delete, and wound up taking the muffler out and going straight pipe. Its sounds real good and loud behind me.. if you want even louder, go with a stack ..

 

Remove the down pipe from the turbo. Drill a 4" hole in the firewall, directly behind the turbo. Bolt a straight pipe from the turbo directly into the cab.

 

And roll down the windows...

 

i gotcha and i plan on putting 5inch turn out stacks on it. im just waiting to get all the parts. i was just wondering what it would do if i took that cat off..

 

Oh it will definately make it louder for now bud.. get rid of the cat and the muffler for now..

 

pull your cat out get a concrete pin and a hammer hallow the cat out .cut the cat on both sides on the weld . get a marker and small piece of 4inch pipe trace the 4inch pipe around both ends of the cat were you cut the weld .now cut the cat slide the 4inch pipe through the cat weld it up. the point to this is to make it look like the 4inch pipe has ben welded to both sides of the cat but now your cat is hallow so you can pass inspection when you smog it makes the truck sond good and you pass smog as long as you dont run a smokey tune flash it back to stock when you smog it .ditch the muffler and stay with a 4inch your not running enough power to need anything bigger.
I did this on mine as a do it your self and it didnt coast me anything. with the stock turbo its not going to be to to loud your going to have a whistle hissing sound your not going to sound like a lb7...... hpoe this help you out you need more info let me know

 

diamond eye turbo pipe, mbrp downpipe (cat delete), 5" mbrp out the back with no muffler.

 

thanks for yawls advise. i will have to look into in all..