I have a 2000 TJ with 107K miles on it.  The other day when on the expressway I noticed that the oil pressure was pegged at 80.  It never went down until I got off and came to a stop.  Then it only went down to around 50, but as soon as I started moving again it went right back up to 80.  I parked it for about 5hrs then checked the oil.  It was full and not bad looking.  I started it up and it went right back up to 80.  Once I started to move it lowered to about 70 but never went down until I stopped again.  Yesterday I just started it to see if it was still doing it and it was.  The oil was still full and not leaking anywhere.  Does anyone have any thoughts?  Thanks for the help.  Eric  

If it winds up to be your guage, Mount your own.  Its a-lot chepper.  I had an oil pressure guage in my 97 brake and the StealerShip wanted $300.+ to re calibrate it!   I mounted my own, It took a few hours & looks great!  

 (I would check your oil pressure sending unit. If Thats not it, set up a test guage & get a real reading)
Good luck