Josh - To avoid confusion, your diagram should show the top and bottom sections of the engine connected.
Also it's worth emphasizing that that schematic is for an naturally aspirated carbureted engine. NA FI S30s have the crankcase hose attached after the throttle plate and the valve cover hose attached before the throttle plate. Turbos have a different setup or else the crankcase WILL get pressurized or the intake will suck in unmetered air (assuming stock AFM is used). I'm not sure of the stock L28ET PCV plumbing.
I removed the PCV system from my car. I have both the valve cover and crankcase vents hooked to a catch can mounted in the engine bay.
R0N - You could try removing the crankcase hose, installing a filter on it, remove the PCV valve and plug the intake hole. If oil stops spraying out the seal then you found your problem.