Oil pressure drops at idle in 1997 wrangler?

I'm going through this same problem, everything is fine with the pressure, then when you drive around for a while and come to a stop the oil pressure drops and the check gauges light comes on. After replacing the oil pump and pressure sending unit i still had the problem. My "mechanic" (who sucks by the way) said the problem would be fixed after replacing the pump, and $400 later the problem was still there. I decided to just buy a mechanical oil pressure gauge from Auto Zone, paid $15 threw it in the Jeep and everything is fine now. The oil pressure is steady at 25psi when stopping now. The check guages light stays on and believe the check engine light will come on because the computer senses no pressure, but i believe you can buy a gauge the connect to your on board computer. Its a lilttle more money though. I wish I had done this before investing money in to the other problems.