Check your vacuum pump ion the passenger fenderwell and make sure its working, if so, its a vacuum leak somewhere. Im chasing the same thing on mine right now. There's a thread at the top of the 7.3 forum right now on
www.powerstrokenation.com about it I just started reading up on last night.
I just run boost and egt on mine bc its a manual. Id run tranny temp with an auto too.