Info is tight in the YJ camp for some aspects of the vac system, in particular the CTO valve and evap canister.
I'm wondering if I can use the diagram in this thread to go by. I ask because everything I read told me to cap the one unused port on the CTO valve, while this guy's diagram leaves it open. I have Elvis' diagram as well, but it doesn't label the evap can at all, and he doesn't tell whether to plug the 5th port or leave it open.
In another thread, someone stated that the canister is labeled for which lines go where, so I'll try to find them tomorrow.
All the CTO valve does is prevent ported vacuum from reaching the EGR and canister before the engine is warmed up. It's just a valve that opens between the vacuum source (the engine) and the devices that use it (EGR and Canister) after the engine has reached a certain temperature. The extra port comes sealed from the factory... I don't really see the advantage of opening it up. At best, if the port isn't connected to anything, opening it will do absolutely nothing. At worst, if the port connects to the others, it will create an enormous vacuum leak.
As for the canister ports, they are labeled on the top of the housing. The Howell diagram above looks correct, execpt the one marked "tab" would be connected to your carb vent (if your carb has one). I would check the top of the canister to be sure though.