There is a plug on the side of the sump with a black wire attached to it. Does anybody have any idea what it is? It is mounted near the exhaust heat shield, and faces towards the rear of the car. You can see it if you look at the heat shield, and then lean over a little as if to look behind the heat shield. It is not oxygen sensor (B23E Australian Spec without this sensor). My only thought is that it is oil temp probe (but my car doesn't have guage!). Thank you for your help.