Cam sensor should only affect a table search criteria for the ECM, there should be a timing chain/belt involved there somewhere. If you pistons are hitting exhaust valves, you won't be running. Dropping the pan probably won't give up all that much unless there is evidence of catastrophic damage lying in the bottom. I suspect you have some damage either with a main bearing, rod bearing or a wrisp pin. If your oil pump is toast you will be doing significant damage the more you run the motor.
From what you describe I would recommend you stop driving the vehicle, pull the motor, pull the bearing caps and rod cap off and see if you have burnt bearings downstairs.
You could always hook up a mechanical oil pressure guage but that still means running the motor. I am not sure if the diagnostics report oil pressure to the ECM, I would start there.
Good Luck. What is the KM on the motor BTW, I had 320K on my 97 and it is still going strong for my brother. Come to think of it, when I pulled the heads off to do the gaskets at 300K there was push rods, so my 97 3.0l V6 was old school with a timing chain and cam, no OHC on that year. Don't know about your year.