Look What I Found

Catch can vs oil separator is just semantics at this point. The principle is to slow down the crankcase gas flow and introduce some obstruction so the oil comes out of suspension. It's important to do this without introducing a severe restriction in the gas flow. Designs that use cheap steel wool or a bugscreen mesh work well enough. However, there are some poor designs like this one with a micron-level filter borrowed from compressed air systems. Those can definitely cause a rise in crankcase pressure, same way a clogged PCV valve can:



Anyway, now that @mquibble posted a picture of his, looks like an ADD W1, a well-designed catch can. The pleated filter he added in the bowl of the can does nothing but shouldn't cause any harm.

 

Not sure how cold it gets where you re from, and how long you've ran yours this year- but just wait until you see what you get in the Winter.....

 

I live in CT and what you see is the result of going through the winter.