I am using a Miata fuel vapor/carbon canister instead of the very large and heavy Subaru unit. The Miata canister has three ports: two on one side (medium sized marked tank and a small one), and one larger port on the other side. I am thinking that the one marked tank should be plumbed to the FFR fuel tank vent, but I don't know about the other two. I have eliminated any connections to vacuum (intake). Any experience/ideas?