Welcome back:
If the oil has been regularly changed, sludge shouldn't be an issue. I would also want the pressure checked with a mechanical oil pressure gauge to determine if this is truly an oil pressure related issue or if it an electrical fault via the switch and PCM.
I really feel that needs confirmed. Otherwise, we don't truly know where to start. Also, when the light comes on for an extended period of time, is there any noise such as ticking, knocking, or anything that seems out of the ordinary other than the rough idle?
Let me know.
Joe
Saturday, July 6th, 2019 AT 7:51 PM