To test your EVR solenoid (black thing) hook it all up. Crank the car. Run a wire from the black or brown wire that plugs into the EVR to the negative on the battery. As soon as it touches the battery, the EVR should open(this means it gives vacuum to the EGR) then you should notice a rougher, slower idle(if the idle slows down when you grab this wire, the EVR works fine). As far as the crazy idle goes...you could clean your IAC valve. It sounds more to me like someone has been tampering with the throttle adjust screw on the throttle body though. Look on your throttle body and you will see a little arm that has two cables hooked up to it. On your throttle body there is a screw that meets this arm. Loosen the screw while the car is running and see if that makes a difference, if not, put it back where it was :-) Sorry about this man, its just kinda hard to diagnose a car when you cant see it! Hope this helps!