Simplified Sequential

[Herblenny]

Hmm.. Seems like you are right..

Here is the RX8 diagram..


Looks like its before the TB.

Air is led from the throttle chamber to the check valve. The reason for this is to prevent the suction of a large quantity of oil by the vacuum when the vacuum of the intake manifold and combustion chamber becomes high during rapid deceleration, etc. Consequently, the amount of engine oil measured by the metering oil pump is supplied, regardless of the vacuum caused by the check valve.

I guess I was wrong Looks like you were right.. just to suck in air and no other purpose. The picture you linked really help me see how it works.. and I also forgot it went in one direction and somehow I was thinking it still sucked in.. I'm stupid like that sometimes..

Thanks for the picture and helping me understand