1965ss

boost is not consistent floor it you can get variable boost anywhere from 8psi to 24psi. it also will bog pretty bad. once in awhile i will get p2187 check engine code lean at idle. anyuone have an idea i think possible the secondary fuel pump is weak . this car has a stage 2 gm performance .

firemangeorge

You could do a search on that code P2187. There are several threads about it.
This one had an easy fix:https://www.chevyhhr.net/forums/ss-s...ss-auto-50932/
Posting the year, mileage and what transmission you have would help. Also, how long you've owned it.

FYI. Nothing called a GM stage 2 that I've heard of. Guess you mean the GM Turbo upgrade (GMTU) also called a Stage 1 kit.
If you have that, with the old style crimp connections, take a look at the lower Tmap wiring. Corroded wire crimps or them hitting against the AC compressor are known to happen and cause performance/boost issues.

Cat Man HHR

Thanks George.
How many times this info isn't posted before explaining the problems.

Blue_SS

Pressure side leak would also give similar results, but it should be more consistently weak and boggy. You probably have your answer already...

Oldblue

The information in his page shows 2008 SS