ST205 Boost Problem, Only hitting 3/4 boost on the stock guage Options

[cax_11]

I got my car about 2 weeks ago, and it does't hit full boost on the stock guage like those I see on youtube, There is no check engine light, I already reset the ecu, one day the boost went right up out of the blues and it pulled like crazy, but next day it stopped, any ideas anyone?? Any input is appreciated, I don't think its a boost leak because it doesn't fall back, it just stops around 3/4 up the boost guage and sometimes crawl up the rest of the way(sometimes).

[schmooot]

my stock gauge doesn't go above 3/4 while the aftermarket one shows 12psi at full boost.

Can you feel a lack of boost or are you relying on your gauge to tell you?