Low boost, won't go, need help

[angcobra]

Update. Solved!
#7 injector had electrical fault that was causing other 3 on passenger bank not to work.
All 4 injectors on each side use a common ground wiring.
When I unplugged #7, --- #5, #3, #1 starting working.
Replaced #7 injector, check engine light is gone, runs great.


Stock truck with just straight pipe exhuast.
Truck was running highway speed pulling 8,000 lb load, check engine light came on and it just started to slow down to the point of not even being able to pull off. Ran scan on it and got code for Exhaust backpressure control failure.
Replaced Exhaust backpressure Sensor, no change.
I have ran every scan test I can run and did some data logging everything seems to be good accept boost level of 3 - 4 psi in park at 3300 rpm, when at the same time exhaust backpressure is 7psi (even with red hose off).
I also noticed on scanner that turbo wastegate goes from 0% to 99% just off idle, I do not know it that is a ECM generated signal or actually seeing position?????
I decided to check for boost leaks, I took the charge pipe off at outlet of compressor. I plugged the pipe and applied 10 psi of pressure to charge piping all the way to the engine cylinders, no leaks other than wastegate actuator line i forgot to plug.

Also, idle is very rough and one injector comes up as high/low error. In drive, on the floor will only get 800 RPMs. Fuel pressure was a constant 60#.