There is a pipe from the bottom of your throttle body that runs to a metal pipe mounted to the rear of the inlet manifold. I do believe that is the pipe to your idle control. Also you have three other ports on the rear of the manifold. One is for the brake servo, one for your map sensor and one that goes to your carbon canister. Try blocking off all these except the map sensor and see if the idle drops. You will have a vac leak to the inlet somewhere.