I have been trying to figure this out and getting no where... first off this is an 07 6.0 with a zf6 manual. Truck starts just fine and idles nice, the problem is the truck feels dead when I hammer on it then lights up great getting up to about 28 lbs of boost. The real problem is when I let off the throttle and press the clutch in to change gears after a hard acceleration the motor contines to rev when I get around 3k it will actually rev to about 4k for just a second even when I let off around 3k. It doesn't push if I'm in gear though not that I notice anyway. Also when I just rev the truck even stopped to over 3k then let off the throttle the engine will come down just slightly then rev again almost like I double tapped the throttle again only for a second. I'm wondering if a fuel related sensor may be going... maybe a icp or irp. The truck also turbo farts when under a hard load which could be a bad vgt or sticky vanes but not sure if that is related to the other issue? My egr is completely deleted aside from the recent airdog 2 all my mods are listed in my signature. I thought maybe it was a delivery problem hence why I got the air dog. Soooooo..... any ideas anyone?_
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_4 inch down pipe into 5 inch stacks... no catCFM large mouth intake elbow with larger pipeS&B cold air intake Edge juice with attitude CS with custom PHP tune. Atlas 80 ficm tune.6.4 banjo bolts, Blue spring, Zoodad mod, Traction bars, counter sunk tool box molded around my stacks custom made by me,Coolant filter, ARP head studs, southbend duel friction clutch, complete EGR delete, DP mod, high idle mod, CCV relocation, 35 inch fierce attitude tires on 17" helo wheels

 

Sounds to me like your turbo needs a goods cleaning.

 

That's one thing I was thinking but could that make it rev slightly longer than when I let my foot off at around the 3k rpm range? Its really odd.