Every time I get on it boost jumps to 13psi just b4 1-2 shift and then no boost. When I turn it off and back on I have boost again. As long I stay under 5psi the car runs great. I already checked everything there is nothing wrong mechanically with it. I see a few trades about the same thing but don’t see what fixed it or what caused it . I’m Fuster rated it with it already

 

Pull the codes. If it is resetting after each key cycle, then a trouble code should be present in the OBD system.
Post the code numbers here (no descriptions) and we should be able to point you to the problem.

 

not a mechanic by any means , but could it be a vacuum leak .. I had one where the airbox pipe goes into the turbo & was not getting much bboost at all -- oh well good luck

 

I checked that but ill check again thanks for your help.

 

P0299

 

Looks like possibly a simple fix

https://www.obd-codes.com/P0299

 

Check the bypass valve diaphragm and the bypass solenoid.

Also check all vaccum lines and connections for leaks, including the vacuum tank itself.

 

You said nothing was wrong with the turbo so it couldn't be the bypass valve or the wastegate.
Does it have the GMTU kit, if so check the Tmap for banging into the AC and inspect the wiring that may have been crimped instead if soldered.
Check the CAC for tiny leaks, the special clamps must be properly torqued.

 

Thanks everyone for all the info we’ll go over it once more tomorrow.