Engine breathing heavily from catch can
 

Hi guys I have a little issue on a 2004 STi as described above.
I have a baffled oil catch can and appear to be getting a lot of oil/vapour escaping from the top vent.
This has never happened before until the weekend just gone.
Anybody got any ideas as to what might be causing it?
I'm guessing piston rings.
I will carry out a compression test and a leak down test to be certain but just wanting to prepare myself with possibilities if people think it might be something else.

P.S the catch can is empty so nothing to do with it being full.

Thanks.

when the rings get bad oil consumption is terrible. the spark plug on that cylinder(s) will be coated too. if you have the cat still fitted it will contaminate that too mate.