Need help identifying sending unit.

I have a 96 Eclipse RS 2.0 There is a sender around the back under the intake that is leaking. Its the one closest to the transmission on the drivers side. There is another one on the passenger side about the same location on the block just more towards the timing belt side. I think that one is the knock sensor. The one that is leaking has 1 yellow wire going to it and the threads are about 5/8" diameter. I would think its the oil sending unit, but I bought a new one and the threads are about 3/8" and it dosen't look anything like the one on the car. All th pics of the oil sender I can find on the internet look like the one I bought. Can anyone help?