Question about S15 SR20DET vacuum lines
 

Hi,

I have the S15 SR20DET. Does any one know what the two vacuum ports located underneath the throttle body were originally used for? One of them has a one way check valve, but both lines are just hanging and I don’t know if they should go any where. I was going to use them for other vacuum uses, but I would like to find out what their intended uses was in the first place.

Thanks.