Yea most Pcv one way valves are used on high performance, or turbo vehicles. Where the manifold can see slight pressure. This is so the crank never sees the pressure from the supercharger, turbo, ram-air..if it does you could blow out dip sticks, seals, gaskets...Where as other cars, it's just a metered hole.
I just did my valve cover and could not find the front elbow anywhere. That's all it was, an elbow. So I'm going to do what this guy did, drill it out. No big deal.

 

Toyota Tercel 1.6L is a high performance turbocharged engine? LOL

You are close. Crankcase ventilation in at least some forced-aspiration engines is done upwind of whatever air pump. Both my Duramax and TDI dump the CCV right before the turbocharger. In the TDI it's just a simple tube with a sponge in it to try to force oil to condense.

Unless specifically required due to air flow, the change from CCV to PCV is emissions-related. PCV systems leave a lot more oil IN the crankcase as vapors are only removed to release pressure. This extends catalyst life.

 

I blew one of those up

 

In a Jeep Cherokee