Just installed a new 4" turbo back exhaust and have a hissing noise from the tailpipe. MBRP muffler and gutted cats...
Sounds completely normal under the hood, but loud hissing noise at the tip. Not a whine like he turbo, just a hiss at idle. Funny thing, when it started it for the first time, it sounded normal for about 3 seconds then hissing.

Is this normal? I am really sure muffler installed correctly and all my joints are tight...

 

can you get a video with sound and post it? And are you sure you don't have a cat stuck in your tailpipe?

 

The infamous Ford 6.0 Jet engine sound...


Josh

 

I guess that's it. Thought that would have more turbo whine and less hiss...

 

Yep sounds about right. Mine sounds like a hair dryer

 

That's it! Sounds like a hair dryer. Kind of strange...

 

 

The 03 turbos have quite a bit more whistle than the 04-up turbos.

My truck has a 4 inch straight pipe, and when pulling a heavy trailer with the Jake brake and tow haul on, it has an ear-piercing whistle when slowing down. It will hit 4-5 psi sometimes when slowing down. I love it!

 

Yeah the 6.0 sounds amazing and I love the hiss. Miles your truck is bad..!