Dead

a PCV valve as we know it. The crankcase vents into a trap and out of the trap it tees off. The part of the tee that goes to the intake manifold(on the 2000 model I've seen it is a indirect path)contains the one way valve. The other part of the tee goes to the pressure regulator valve in the intake hose(on some 1.8Ts a vent Ys off to the valve cover gasket in between the tee and the intake hose.)Under vacuum the one way valve is open and the crankcase fumes are pulled into the intake manifold. When boost occurs it shuts to prevent the crankcase from being pressurized and the crankase vents into the intake hose.

Lambo-Bully

When my setup was running, I originally had that piece at the turbo inlet in place, and noticed a lot of oil residue in the turbo, so I removed it & eliminated that whole route, just let it go to the intake. The fuel purge system can also be changed in the same way, eliminate the path that goes to the intake side of the turbo...

xr4tic

For the most part, it acts as a restrictor.

It's probably not a big deal, but it couldn't hurt to put it in. If you look at Dave's pic, the outlets are 90 degrees from each other, so it would be pretty easy for you to put one in.