This does sound like a faulty oil pressure sensor. To make sure, you will want to install a " T" fitting onto the sensor mounting hole and then connect a manual oil pressure gauge. Use the manual gauge to determine if the vehicle's gauge is reading accurately or faulty. If it is accurate, check your oil pump. If it is indeed a faulty reading, replace the sensor. It is located on the top rear of the engine. Disconnect electrical connector and unbolt from mounting location to replace.