There are 2, one for your gauge and one for you computer. When you stand infront of yourcar facing the engine, the one in the intake on the right side is for your gauge(one wire) and the one on your left side in the metal tube (2 wires) is for your computer.

 

don't take the wire off and ground it out. this can fry the instrument panel voltage regulator. buy a new one and don't use teflon tape to seal it