False information!

Your OEM system is not closed.

Valve cover on the left head is closed off by PCV valve. The one on the right is not. It plumbs into the intake tube which is constantly open.
So there are no need to maintain a closed system.
Everything is a preference.

Most closed catch cans designed to vent only one head. People forget that we got two and there is another line that vents into the intake.
With open can you can vent both. I like open because I guarantee that there is no oil vapor goes back into the intake, with closed you cant. Some vapor still escapes no matter how good your can is.
With open can you do have to deal with oil smell outside the car. Easiest way to manage it are oil soaking pads that you just replace with oil change and never have to worry about your can filling up with oil.

Best can design IMO would be a closed can that you can open and put oil soaking pads in. This would be a 100% can that has no smell. Oil pads would absorb all oil vapor and never release nothing back into the line as long as you replace them frequently.

 

There are many builds where people have used breathers. Just because it may smell doesn't mean it cannot be done.

 

There is never a reason to replace the PCV all you need to do is clean it! Remove and shoot a small amount of carb cleaner inside and shake it. If it rattles it's clean and working as intended. I keep carb cleaner in my garage, it's so hot it will clean anything metal...just keep it away from flame!!!
Gary

 

even the port from the rear driver valve cover going into the intake is part of a closed system. it is after the maf... metered air. so just make sure that you plug the port in the intake tube from that valvecover port if you want to run an open breather, otherwise it will leak metered air and won't run properly.


I'm going to work on mine today. can needs baffles, maybe a restrictor

 

but the system is not closed. Air filter always remain open and air always gets in that port when engine not running. So vented can does not change anything but the fact that it vents everything out into the atmosphere.

 

I stand corrected. Forgot what type of maf this car has.