2018 Ram 2500 6.7 full delete with approx. 25000 drive since deletes. Roughly, 2 weeks ago is noticed a loss of power while traveling on the interstate. Started paying close attention to gear shifting to rule out transmission issues. Shifting up and down was fine. Changes the display on my tuner ( race me utlra) to view boost psi. Noticed it would occasionally hit approx. 32 which used be normal acceleration boost range. Most of the time I'm getting below 10 psi now. Stock turbo. No increase in engine Temps, air flow is good....
I did notice today, will truck is in park or N, I have about 3 .5 psi of boost at idle. I slow pressed the accelerator to see if the boost would build with rpms; at 1100 I lost all boost. I can push pass it to around 1500 rpms and it will slowly build back to around 7...
New to working on diesels, not at mechanical idiot by any means though. Guys teach me something on this one please.

 

When your revving it up is it in gear? In neutral, it really should not have any boost. Have you tried changing the tune? May be a software glitch..unlikely but its a cheap attempt. When you say full delete, I assume you mean nothing impeding the exhaust? Have you looked to make sure none of the exhaust is bent or creating undue back-pressure? Nobody stuck a potato in the exhaust pipe? LOL