There is a oil pressure switch or sensor located next to the oil filter in your 1997 Nissan sentra gxe 16l that appears to be leaking oil what is this part and how do you replace it?
well you said it. Oil pressure switch or oil pressure sending unit.most cars have both.If it has one wire it is an oil pressure sending unit. if it has a plug with 2 or more wires it is an oil pressure switch and sends a signal to the onboard computer. remove the wire either a nut or usually a plug.some sending units take a special socket but if you can get a wrench on it turn it counter clock wise and unscrew it. when you get the new one it will have a red material on the threads, this is a sealant.thread the new switch snug and put you plug back on.