Ok here is my problem. I have been getting a low oil pressure at idle, give a little gas it goes up to normal pressure then drops back down. I replaced the oil pressure sensor, and still get the same outcome. Oil and filter is all brand new 20 miles ago. Yes I was having this issue before the oil change as well. I went and got a manual Guage kit and put the Guage on. I am showing a good 10 psi at idle and about 40 of I Rev the motor. Other thing that is confusing is without the oil pressure sensor hooked up and the plug just hanging there I show about 40 psi on my dash. Shouldn't this show 0 with it not hooked up? I even took the oil pressure sensor and plugged it into the plug and just let it hang there not screwed into the engine and I still show 40 psi on the dash. Any ideas or ways to track the issue down?

Thank you
2004 jeep wj 4.7

 

I know I'm a bit late but this costs you nothing to test. Try draining half a quart of oil and starting engine and seeing if oil pressure changed. Then if no results try adding 1 quart then testing.
To much oil can cause loss of pressure, it causes oil to froth and aureate adding oxygen in the engine dropping oil pressure and HP.
Losing a quart can allow you to drive at higher RPMs while gaining horse's.
It could be a bunch of things but I've had this issue.
Did you install an Aftermarket oil pan or filters?

 

I have tried everything including draining some oil. I have even replaced the entire guage cluster. I cannot get this low oil pressure to go away.