Without that little metal piece, it's almost like there's a vacuum line stuck right in the oil pan. The best solution would be to install the PCV baffle. Another possible solution would be to replace the PCV assembly at the back of the intake with a breather, maybe at the end of a hose., and the one of the valve cover with a breather. That should eliminate the vacuum pulling the oil up into the intake, the filters may get soaked with oil over time.