Boost Gage problem.
 

I recently purchased an 02 SSEI and the boost gage reads below 0 unless you give it some gas. According to the owners manual the gauge is centered at 0 every time the ignition key is turned on. Mine does not do that. Is there a problem with my gauge or is it normal.
Thank you for your help.

I think its supposed to zero itself at 0 until the engine is started. Remember, at idle, your engine is producing a vacuum at the inlet, there is no boost until the SC is spinning fast/increased volume to offset the -pressure. On a normal SC 3800, I believe you should see about 9 psi at WOT on premium fuel.

Yeah, what Mike said ^^^^^^^

Normal to show a little vacuum at idle. While you're fiddling with it, make sure the engine air filter is clean.