My oil pressure guage had developed a mind of it's own, mostly staying pegged to 80 psi. After talking to a buddy who is a GM Tech, he said it more than likely was the sensor.
My mission... change the sensor!
The GM Service manual says you have to remove the intake manifold
because this sensor is buried in the back top portion of the engine. I was able to see it from the side and was able to feel it with my hand, so I figured there had to be another way.
All you need to do is...
Disconnect both fuel lines from the intake and remove the PCV hose. This give you all the room you need to remove the electical plug and get a socket on the sensor.
I removed the OEM sensor with a 6 point 1-1/16" socket, swivel, and extension. It fit beautifully and got it right out.
I had to order a replacement sensor from O'reilly ($45). The BWD brand sensor is taller, meaning you need to use a deep well 6 point 1-1/16" socket. The only one I had was an impact socket that has a very thick wall. It wouldn't fit down over the sensor because of the tight area.
Sooooo, a trip back to the parts store to get Lisle Tool 13250, Oil Pressure Switch Socket. It is a thin walled deep 1-1/16" socket made for these sensors. You might could get a regular, NON impact deep well socket in there, but the special tool was only a dollar more so I got it.
Got everything tightened up, all hoses/lines re-connected and fired her up. No problems, no leaks, no warning lights.
Life is good (until the next thing breaks).