Hi, do you have a sport 4x4? The sports didnt come all wheel drive. Only some of the V8 explorers did.
I had oil dripping on my catalytic also and i thought it was the intake gaskets because they needed to be done. After replacing the intake gasket, the leak continued and I determined it was the oil pan gasket. Check that out and your rear main seal I think should be checked also..not positive. Its easy to see a leak in one area and be so focused on it that you dont notice another or multiple other leaks. The leak wasn't big, but when its landing on the cat/o2 sensor, I know how annoying it can be.