On my 15 STX15f it seems like I'm sucking a bit of oil through the catch can into the air box intake. It was doing this with the air box in place as there was a small drip at the bottom of the pcv line inside the box when I removed it. Adding a free flow intake only made things worse as it increases the vacuum on the pcv line before the throttle body the way I have it configured. I'm thinking of adding a restrictor to the line to cut some of the vacuum through the hose or a pressure relief valve to keep the pressure static (thought that's what the pcv was supposed to do) .

Is this normal on these engines? I have checked my oil and it's right where it should be, not over filled. Any idea how much the vacuum should be on the catch can?