Have an 08 HHR SS. When I first turn it on and drive, it runs perfectly. After about 5 min the boost falls to about 2psi until I turn it off. When I turn it back on, it does the same thing. Any ideas on what could cause this issue?

 

You should start a new thread. Does your have the GMTU upgrade done to it?

 

Could be a cracked I/C pipe

 

Cel?

 

Maybe the OP will come back with some more info, but I'm not going to hold my breath.
He posted up 2 other questions but never came back to those.

 

Agree with donbrew, you need to have someone pull the CEL codes, your local auto parts store may do it for you. Post the code(s) up here, and we'll help you. Just the code, not the descriptions, which may be misleading. I'm expecting P0234 (that's a zero, not an oh), which usually points to the boost control solenoid.

 

This is my guess as well.