What is this part off of the Oil Filter fitting cast???

I have a small oil leak beside the oil filter on my 4.6 litre V8 engine in a '95 Mercury Cougar.  There is a 3 inch elbow which is part of the casting where the oil filter fits. Attached to this elbow is a sensor or line of some kind. Would this be the oil pressure sensor or something like it? Is there a seal or something that can be replaced or does the unit have to be? There is a picture attached shot from under the car facing up, any information or help would be greatly appreciated.... Also email is available at kennedytracks@bell.net