Hmmm...you gave us some stupid reasons for the poll Jay...
Ok--so when you say you bypassed the STS venting system--you are talking about the BOV setup where it goes back into the intake, right? So, the only advantage is releasing the the off-boost into the atmosphere--but that should have no effect on the oil pressure, right? I know the STS kit needs an oil tap from the motor...somehow that is the issue??? I don't think the motor has enough uuumph to blow the oil filler cap off unless it is blowing itself up.
And when you say "blew oil out," are you talking about it dripping out of the cap? Or the neck at the valve cover? Or did it blow it the eff off? We needy more info son.
Is the oil filler cap locking into place? Those things are so fu--(whoops, we almost had an infraction here)... Those things are so stinkin weird that the cap could be stripped out or something.
But still, we need more info!