Re-learns can be helpful...hopefully that's the case here.
Catch can - are you finding quite a bit of oil in it, or is it mostly water?
I'm of the opinion that the water vapour it's getting rid of HELPS combustion, mileage, power and emissions. I removed the setup I had on my PCV re-route and gained an MPG or two back. The oil it collected was negligible to nil, and the water smelled of gasoline, but nothing separated out when I let it rest.