All right here goes, my 06 140k 6.0 stroke towing up to maine last weekend towing a 6 ton equipment trailer with my race jeep on it, after 2 hrs at 75 when i pulled off hwy95 the turbo wouldnt come up huge black clouds truck wouldnt move, i had to put it in 4 lo and idle up a steep hill. Engine wouldnt rev clouds etc, on the downhill back in 2 wd once it moved up the turbo eventually responded clearing out the smoke n took off like a raped ape, i babied it 15miles to the track. let it sit for 20min still did it clouds. I was gonna leave the jeep n trailer at the event, truck never got hot , had cooling pressure, oil was 3/4 on the stick i kno its due it is t6 rotella 4k on it , I always am religous about oil turbo cool down, motorcraft filters etc..After the long day it still was doing the no turbo huge cloud thing wouldnt rev up, I unhooked the turbo solenoid, and the motor revved back up where it should just no turbo, I hauled the trailer up to the hiway, pulled into a gas station and plugged it back in and it worked all the way home....I though i would clean the turbo maybe i overfueled a bit coming up and maybe i sooted up the turbo , I had no cel lights no wrench lights,
Truck has had issues, lost # 5 injector repleaced that and the stand pipe o rings on that side, still have to do the other side, delete, studs etc just money issues now i keep spare injectors in the center console hahaha

 

My first though is a stuck EGR valve, might be worth wile to pull it out and give it a good cleaning, that would be first on my list,cheapest too.