is this on a seperate mechanical gauge or are you going by the cluster gauge?i have this same problem and i not sure how 2 fix..... 01 ssei bonnie- oil pressure 40 to 120
if you get a T you can hook both the mech and electric gauges up. personally i'd hang the mech on anyways, but these oil pressure senders are known to fail by passing oil through to the electrical terminals, if it's unplugged and the female wire terminals are oily (trust me you can tell) chances are the issue lies with the electric oil pressure sensor. other possibilities include chafed/grounded wire or a gauge issue, start with the sensor, and visually inspect the wires...i have had clusters (if your good you can replace just the gauge) go bad but in my experience the oil senders are the proverbial "thousands of lemmings off a cliff"...im going by the cluster gauge in the dashboard.. it just happened. a mechanic will test pressure of engine for 80 dollars. not sure if i should do this if its just a bad sensor or a stuck pressure release valve. maybe its the gaug? that is prolly step one..... i think it is prolly the pressure release valve- is that easy to fix?