Turbo sounds like creating back pressure

[farmallcrew]

You know how when you start the wonderful 7.3 in the morning, and you get the turbo to blow off "phhhhhhfffffff" like air comming out of a rigs tank, blow off valve. well every once and a while when i start it up and drive the turbo wants to, i beleive create back pressure and blow off, it happens around 1500 rpm and there is lack of power durning this. to remidy this i get the rpms higher to bout 2000 then it blows offf and turbo sounds fine. or is this a valve that is not opening and closing when it should???? have any of yall had this problem????

[screech]

Yes, this is normal. It is the EBPV (exhaust back preasure valve). It creates back preasure when cold to warm engine when cold. Louder with dounpipe and strait pipe.

[sea71]

If its doing this after the truck is up to temp, then the ebpv is sticking.