Isx help

[W9gator]

Hello everyone new here . I have a 2016 isx cm2350 yes its demandated no I do t want to hear it . I can see on here the feelings of them
Not going to change anything now anyways. I've had the truck for 3 yrs now and it's run great no issues was getting 6 mpg running 3.25 gears 13 spd anyways recently had it at the dealership because regular shop was too busy . They did a dot and a overhead adjust because it was due and also replaced exhaust manifold because it was leaking. Well they found my cac was leaking to so replaced that. Got truck back and have had nothing but issues with it since. This was about a month ago now. I lost almost 2 mpg on fuel and am now running higher turbo boost . Took it back and let them have it
They ran e tire fuel test came back said my fuel pump was the issue amd that when tech ran overhead must've did it wrong because exhaust valves were tight . Their words not mine. Well replaced fuel pump thank God as it had the dreadful ceramic plungers in it and they were still intact luckily. Dealer assured me that would fix my issues well it hasn't. I did pick up about .5 mpg on fuel but haven't gotten back close to the 6 mpg mark. Oh truck is a w9 studio so I'll take 6 mpg all day every day. My question is what to look for next? My tune is not out of a box and the local guy that did it is well known for doing good tunes . He is even recommended by some of the dealers in area. That being said doesn't meanuch in the end. I'm just trying to get to the bottom of this quickly. The dealer wiped out all the active amd inactive codes but the big thing is I never had a light come on or even active codes. It's been a month since they wiped them out amd I still have no codes showing up. So recap I was getting 6 mpg fuel and running between 30 and 38 psi for boost uphill flat ground was 10 to 15 psi . Now I'm at like 4.7 mpg amd 40 to 50 psi up hills amd 20 to 30 psi flat ground. Oil temp is always around 210 215 amd water only hits 210 once in awhile pulling hills. Any help is appreciated even my normal shop is scratching their heads because no codes. Also I pulled map and exhaust sensors amd replaced both . I'm running maintenance free crankcase all new fuel and air filters since it started. My normal shop said engine seems to be strong nothing in oil sample amd checked blowby couldn't even get 7 inches of water out of it. Engine has 745k on it amd has never been opened up except to do overhead .

Thanks everyone [/size]