wow the oil pressure sending unit is only for the oil pressure dummy light. It has nothing to do with the way the car runs. To the guy saying his car wouldnt start with it unplugged then there was something else def wrong. That just s dummy light sensor to let you know its got atleast 5 psi of oil pressure. Now there is a knock sensor around that area, closer to the bottom of the intake manifold flange. That could be the wire, but the car will still perform the same with or without it hooked up. It will just throw a code. Now to know what the code is just jump the two jumper wires underneith the pass side dash. Its usually a twi wire grey plug. jumping that will tell you in blinks what the code is threw the check engine light. But I have to say again the oil pressure sending unit has nothing to do with the car running. That wire dosent even run to the ecu, just directly to the cluster.