Has anyone done it yet, and does it sound.

Never done it but I've heard them. Not very loud. Lots of turbo whistle

If you remove the muffler but keep the catalyitic converter, the exhaust note will make some rumble upon startup and when your heavy on the gas.

I heard one that sounded like a vaccuum when he gave is some fuel. Then I also heard one that had a real loud turbo. From a block away, windows up, and radio on, I could hear the turbo plain as day.

I have one no cat or muffler it's loud:ro) :ro)

Diesel Jockey Quote "Then I also heard one that had a real loud turbo. From a block away, windows up, and radio on, I could hear the turbo plain as day."

That is usually the 03's that are super loud. 04's changed some things in the turbo to quiet them down.

I installed a Straight Pipe set up on a Late 2004 6.0 that (on customer request) side exited in front of the rear tire. The entire system couldn't have been more that 9-10 ft long. At idle the truck sounded a little wierd with the warm up valve 1/2 way closed (Vacuum/high pitch whistle) but under hard acceleration it was exactly what the customer wanted. A little Harley Davidson mixed with a 747 passenger jet on take off!! To each their own!