Well heres how the pcv system works... Fresh air come in the tb area, before the throttle plate and after the maf. This is why you were pressurizing the crankcase, not really the right testing to be doing but oh well. The air then goes through the m90 passage to the lim passage and into the front head passage down the block into the crankcase. It then continues the airflow to the rear head where it goes into the back lim passage back up into the m90 after the throttle plate. This is a metered air leak and all it does is create a crossflow to vent and remove the escaping crankcase gases from building up and blowing out oil seals in the block. It is also there as an evaporative emissions device. Most people just run a breather when they mod but if your state has inspections you may not pass if you disable it.