Not sure if your trying to correct me or make things clearer for old mate. But the whole system is called pressurised crank case ventilation. The check valve at the back is for when the throttle is closed and draws in gases under manifold vacuum, and the breather is for when the throttle is open and the check valve is closed, hence it is fed into the intake to be burned for emissions reasons, rather than venting to atmosphere. Its all part of the PCV, the little plastic check valve is not THE PCV. You think theres alot of oil in your intake? Pull your throttle body off and have a look in your manifold...