S14 Crank Shaft Position sensor??? help

[DJTw33k]

OK...here's the info.

I did do a search and found some info, but it wasn't to what I was looking for. Here's the info:

I have a S14 1996, zenki. I'm not the original owner, but I had to go get it smogged, everything passed except something ticked the CEL. I ended up failing the smog test due to this thing called "Crank Shaft Position sensor". It was kinda weird how I would fail for something that doesn't seem relevant to smog, but anyways. I take it to a mechanic and he showed me the sensor, which is pretty simple looking. Found out that my transmission didn't have the sensor installed at all. This sensor is located right behind the engine, in front of the firewall and there's a slot(hole) that plugs into the top of the transmission. So, i got a mechanic to get the part, but we can't find the wire to plug it into.

I then took it to another mechanic and had the car lifted up, and we found a 3 pin plug near the transmission. This new mechanic was telling me that this plug is the one that will plug into the sensor but will need a cable to convert it from the 3 pin to a 2 pin.

My question is this, the crankshaft sensor is a 2 pin receptacle, so I would think that a 2 pin plug with wire would have to be plugged into it. I've never heard of a 3 pin plug that would convert to a 2 pin in order to plug it into the sensor. Has anyone heard of where a 3 pin wire extension would be needed to plug into a 2 pin crankshaft sensor?

Please help, I've never encountered this problem before. Thanks