Cummins x15 low boost after delete

[Techmech]

Onepl........if you just read you could most likely fix your issue. In this very tread RAWZE just pointed that the Intake Throttle valve butterfly diaphragm should be removed.
You pointed that boost goes back to normal when you disconnect the valve.

I am not saying that you should not have your program checked but at least read the whole tread twice, understand pointers given and than ask for help.