Chirp sound

[08Powerstroke6.4L]

So I started noticing a funky chirp or slight squeal when I goose into the throttle while already rolling. The best way to describe the sound is its very similar to the belt chirp right when you shut the engine off. It wont do it every time only occasionally and its only when Im cruising at low boost then stab into the throttle id guess 80% or so. It doesn't do it floored or when shifting through the gears or at idle or steady throttle cruising. Im not sure if its the belt momentarily slipping while the rpms shoot up or the turbo or what but ive never noticed it before and its loud enough to get my attention. Does it with AC on or off as well.
I have had the water pump/tensioner and belt replaced about 5,000 miles ago so all those parts are pretty new. Inspected the CAC boots to look for leaks and noting seemed to be obvious there either. Truck runs good like always, So im really puzzled. Any ideas?

 

[diesel2121]

Sounds like the up pipes to me

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[08Powerstroke6.4L]

I have the BD manifolds and up pipes that were done about 15k miles ago.
So I finally took it to my mechanic and he looked it up and down and all Underneith and we determined it is possibly the fan clutch. The fan clutch was replaced about 500 miles ago and he said since its new and still pretty tight it could be squeaking when the rpms increase at a rapid rate and the fan is engaged.