I have been seeing some weird oil pressure gauge fluctuations lately. Recently I changed the oil pressure sensor at the back of the block by the camshaft sensor. Before I was getting 40 -70 psi and now I am getting 35-55 PSI and the pressure is going up and down 10 or so PSI when rpms are held steady at say 2000 rpm. I have seen a couple threads regarding a worn pickup tube o-ring and was wondering if maybe that was the issue. Also, I don't know why the oil pressure would vary so much after changing the sensor. I am guessing the original was clogged up or something? Thanks for any insight.