There are two things that can cause this condition.The first one is a defective sending unit and the second is bearing wear.I would install a mechanical gage where the sending unit is(by the oil filter) and with the engine running at normal temperature see just what the oil pressure is reading.If it is below 8psi you have internal engine wear on the bearings.When the engine is cold the metal bearings are not to loose but as the temperature goes up the metal expands and that is why the oil pressure goes low.Have the pressure checked with a gage and see just what is the problem.
Okay: I'm really car illiterate. I was told by a local mechanic yesterdy (That has not looked at it and only knows what I told you), that it was probably my oil pumo, which would cost.... He didn't say, but a Whole Lot to have replaced... Is this what you are suggesting? Also, where can I go to buy a pressure gauge checker, or where might I go to in order to have it checked? What you say does make sense. I take it that, if it's the sensor, don't worry about it. But if it's the bearings, what might I be looking at?
Oh: And if the reading is correct, is there anything that I can do to minimize damage/ keep the car running indefinitely? So far, it's running fine....
You can get a mechanical oil gage at most parts houses for about $10.I dont see this being an oil pump replacement as the pump usually works or it does not.If the bearings are the problem you can have the bearings replaced if the crankshaft is not to worn.The job calls for about three hours labor which includes checking the bearings for the correct fit.If you are planning to keep the car it is a small investment unless you have to replace the crankshaft.If the crankshaft need to be replaced the labor is about six hours (still not that much time) and you can get a crank kit for under $500.All in all you should be able to get your engine fix for under $1K which is alot lower than trying to get a replacement car.You may get lucky and it is just the sending switch but with the model year I dont thinkl that is your problem.If you do the repairs plese get the oil leaks fixed.Have a great weekend and if you need further assistance please get back to me,Don