Yes before I changed stc fitting and dummy plugs I checked the ficm it had a steady 48 v
I guess i will look into a.scanner. and a fuel pressure gauge.

 

When's the last time fuel filters were changed? What oil are you using? What oil filter are you using? When's the last time those were changed?

When did this all start? We really just need more info. Read the sticky at the top of the 6.0 page for new guys.