ISX 15 Low Boost

[Amarchionda]

Hi everyone

I just bought this truck it’s a cm870 CPl8518
And the trouble I’m having is I only get 22lbs of boost and the Egts will easily get up over 1000f just bobtailing. I also hooked my empty 53’ steep deck trailer to it and it’s the same for boost and Egts. The truck seems like a dog. The other thing is the engine brakes seems to not work correctly. When I have it on the high setting it only bumps the boost up to about 2-5lbs. Where do I start on this? Thank you!!