Please tell me what this sensor is and what it does. It is screwed into the block just behind the intake manifold on the driver's side of the distributor. It looks like an oil pressure switch. It has two terminals but 4 wires coming out of the harness. It does NOT appear to be part of the ECM system as all of that has been removed. The oil pressure gauge sensor (one-wire) appears to be on the driver's side of the block just above the oil filter. So, what does the sensor in the pics do?

 

I may have figured it out. The gauge in the instrument cluster is hooked to the sensor in the block right above the oil filter. The sensor (or switch) behind the intake and beside the distributor may go to a dummy light (?) Does anyone know what else it does besides this?

 

This is the oil pressure sending unit. The two most common places they are located are above the oil filter and the one you have in the picture. Either area will give you the same information. Was more common next to the distributor, not sure exactly what year is was charged to the oil filter area. There a difference between the one used with a gauge over the car with and idiot light .