[ForteGT2]

Adding an oil catch can in the hose from the valve cover to the intake is not a bad idea. It will not affect the engine operation or fuel mileage. It will reduce the amount of residue that eventually requires cleaning of the throttle body. During normal engine operation the engine is ingesting minute oil vapor...during hard accelleration the engine can ingest engine oil through this hose. An oil catch can will eliminate some of the oil and oil vapor from getting to the intake. If someone made an oil catch can that looked good on our engines I wouldn't mind installing one. I just don't care for what's out there -- fit-all type catch cans.

 

[ForteGT2]

Looks like the double nipple conector is their filter. If the can is just hollow then it wouldn't serve its' purpose unless you have lots of oil coming through your tube. I like the lawnmower filter idea the best -- stuff the can with it and then it won't matter which outlet goes to the engine and which one goes to the intake. The pictured can has an indicator on the side to let you know if the can is full -- you won't really use that on an N/A car unless you have a really worn engine or you are driving wide open all the time!

If you look at older carbureted cars you'll see that they did put a filter inside the air cleaner assembly where the PCV hose connected -- served the same purpose as a catch can. Required you to change them at certain intervals or when dirty.