No boost......no power

[Roysbigtoys]

I have a 2009 Peterbilt 386 w/485 ISX motor w/566K miles, that has been de-mandate the Rawze way about 3 years ago. That's only about 50,000 miles for me, an excavating contractor. The truck has run great and my oil is getting cleaner every oil change. The other day it lost some power and boost. I found that the short tube between the venturi tube and the EGR tube developed leak, so it lost power and boost. Replaced the tube, ( I also made and installed a spacer plate on the back side of the EGR cooler ) but still no power or boost. I was having some trouble with the wrong date on my insite, so I limped it up to a shop where the supervisor hooked it up and said the IMAP sensor got cooked. Installed a new sensor and truck had boost and power again, bob-tailed it home and it ran as it should. A couple of days later I tried to move some equipment and it had no boost or power again. I thought maybe the sensor went bad and replaced it....still nothing. So I replaced the pigtail going into the IMAP sensor thinking maybe it got cooked also. Still nothing. In the meantime Big Roy from the forum ( who also helped me with de-mandate and other issues.... ) was able to help me with my insite. Today I hooked it and I have no active codes, but still no power.
What am I missing?