One is fuel feed and one is return, what's the third?

 

It goes to the EVAP canister in the back driver side of the car

 

Exactly

 

what's the EVAP canister for? Is'nt there a vaccum line from the intake or something that goes there as well?

 

Yes, that is what the vacuum line is for. It pulls vapors from the gas tank to be burned in the engine.

 

Follow the "3rd line" and you will see it drops out of the bundle along the front/middle of the drivers side of intake manifold, connects to a u-shaped metal tube that turns toward the front of the engine, wraps around under the throttle body, changes to rubber, and goes up the passenger side of the intake to the EEC purge solenoid, mounted on the bracket that sticks out of the passenger side of the manifold. From there a vacuum line goes to the passenger side of the throttle body.