It was a bad solenoid sensor in my transmission. Just had it replaced and my engine sounds and runs alot better. No more power lagging.

 

yes check your egr if you don't want a delete you can always get the better beefier egr but that's ur choice. also my truck has an upper fuel pump going into engine one mounted on frame in middle and one in fuel tank found out that hard way with similar problems. some idiot before me looks like he added one? idky but the specs on my truck says it should be 2 fuel pumps idk where the hell 3rd came from.

 

I keep talking to the dealer and they won't say which one was replaced. The way he described it was it had VERY low fuel pressure when it was in and the new pump/injectors fixed that. Just all of the sudden one day my gas mileage dropped significantly and I have no explanation for it.