I'm sure this has been answered already, but I searched and couldn't find an answer.

I have an 09 SS/TC and recently started having an issue with boost. I usually boost to around 22psi, but recently I only boost to about 14psi, and then it drops to around 10psi and hovers there. When I shift gears, it starts all over, boost to 14 drop to 10. I've heard that it could be a bad BEVERLY?

The car has a K&N intake, Opel injectors, ZZP downpipe and exhaust, GM Stage 1 sensors, and a ZZP tune

 

First thing I'd look for is a leak. You might have to pressure test the intake plumbing to find it.