Mack AC460p 2006 Stututu "Flutter" sound

[markoni]

Random lose of power/boost with that Stutututu sound/flutter sound.

Hi, does anyone have idea what this sound could be?  
https://youtube.com/shorts/j1MNYVv77pY?si=HYXggbU_fWp5j2Pg 
Flutter sound ....I have 2006 Mack CXN613

I'm driving like this for months and can't figure out the problem... So it's making that sound stutututu "flutter sound" and when that sound come my turbo is horrible and truck is dragging me down/slowing me down..after some time ( 1-2 hours goes back to normal. 
Thank you

[Joey Mack]

Check the EGR pipe that comes from the top of the intake over to the EGR. There is a brass check valve inside the top of the intake. They can get sooty, and ive even found some that got loose inside.

[markoni]

Thank you for your fast response.... I will try!!