Hi all i hope someone can help. We cleaned out the PCV on the car yesterday, all hoses plus the separator tank. I am confused as there is a connector where the main vent hose goes into the air intake pipe just after the turbo, which has an electrical connector, but does not seem to have anything inside, not that i can see anyway. Should it be a valve or is it a sensor?

Likewise the small pipe running into the intake manifold ...should it have any valve or is it just a free passge for fumes regardless of manifold pressure? To me it seems there is absolutely nothing to sprevent boosted intake air pressurising the crankcase, and nothing to stop crankcase air being drawn into the inlet, after the throttle body and bypassing the IAC.

The haynes manual is usless in this regard. Has anyone got a schematic diagram of the pipe run and/or any insights? In particular should there be any kind of check valves?

As an aside, having cleaned it all out, the oil fumes from the filler cap have reduced, but my son is reporting reduced levels of boost. Wondering if the cleaning has maybe dislodged some one way valve or other maybe?