Manifold pressure sensor unplugged
 

I have a 2000 excursion with bone stock 7.3 powerstroke.
Turbo only builds 5psi ,@ 3300 Rpm. Truck feels old.
Unplugged the manifold pressure sensor. This thing runs like its brand new. No smoke unless I just throw the coal to it. No service engine light. Only bad spot is between 3rd and 4th gear it cavitates and lunges into overdrive then we are off to the races again with a slight trail of black smoke.
Plug the sensor back in and just blah old truck.
Changed exhaust back pressure sensor and cleaned tube and connections at both end. No change.
Yes I put a new manifold pressure sensor in. No change. Runs old plugged in. Unplugged I love this truck all over again.
Turbo is gt38 with wicked wheel. So not "bone stock" but I have tried everything to get more than 5psi boost.
In your response please don't abbreviate extremely important parts. I have to stop reading google that then go thru pages of possible meanings just to find out it has nothing to do with anything. Thanks

Helllloooooo
 

Please help

Check the rubber hose from the MAP sensor ( manifold pressure sensor) to the intake "Y".
There is a convolute wrap covering the rubber hose. The hose may be cracked right by the nipple on the Y.

Thx I will look at that today. Thank you
 

Thanks