Erratic Oil Pressure for 2004 Chevy Silverado

I just had my oil changed and I noticed erratic oil pressure readings. Would this be the oil sending unit or the pressure gauge itself or something else completely?

Are you connecting the recent oil change with the erratic readings? in what way?

Are you sure the change came after the oil change?

Have you made an underhood inspection (including oil level?)

Which engine? I can look for any TSB’s regarding erratic pressure readings.

I have checked the oil levels and they are good. I did not notice erratic readings until after the oil change but I don’t think there would be a connection between the two but I am trying to pin point what may be causing the erratic reading. My truck has a 4.3 liter V6 engine.

After I saw the erratic reading, I took it back to the place that change the oil. He said it may be the oil sending unit. Then I dhowed him that the pressure gauge would stay at 40 after I shut off the engine. Yesterday it whent passsed 80 and kept on till it pegged out. He said it may be the gauge itself our some wiring to the mother board. My engines running good and no service engine light has come on. I am at a loss and hope it does not cost alto to fix or if I need to fix it.

Some of these Chevrolets have the sending unit back by the distributor and you need a long deep socket to remove it.