I am getting Closer to figuring this out .
MY orignal tuner completely screwed the pooch So I got a copy of a similar trucks tune and made minor edits. I Have an issue that drops codes ranging from ones I know of and new ones from Brake booster and up down shift switch which have me leaning toward vacuum issues.
I finally got it to happen on datalogged run. you can see at the end where power was reduced. Looks Like my main issue to me is too rich and O2 is error me into reduced power . Am I correct ?