I had mine plumbed backwards, thinking that the screen and honeycomb should go on the vacuum side, when in actuality, I read some installation instructions the other day, that stated that the screen and honeycomb should go on the PCV valve side, to help separate and precipitate the oil and moisture out of the air as it flows through the catch can. So, I corrected my mistake the other day. Not sure how much of a difference it makes. I also added about 80% of a stainless steel pot scrubber to the inside of my can at the same time.
it's definitely confusing, especially these which doesn't really have a pvc valve as I think of them.
the scrubber seems to be the ticket that actually makes all this work.
hopefully you catch some oil.