yea i know how they hook up i had seen a post on here awhile back where someone put a clear gasfilter on the pvc vavle hose and i was trying to rember why i did asearch but come up zip
It was done to test and "see" if your PCV is sucking oil out of the rocker cover, that's why they said to use a transparent fuel filter, so you would be able to see any oil inside it.