MY 2003Ford Explorer xlt I ran out of Oil 2 days ago my crankshaft turns my belts turned everything turns but wont fire up it's almost like it locked but Is there possibly a sensor that might fix it

Cars do not run out of oil. The 4.0 does use oil between oil changes and normally requires adding oil at some point. If you ran it dry you may have burned up the engine. First. Did the engine kill while you were driving it? Normally if an engine dies due to oil starvation it will be begin running real bad and lock up. Turn the crank over by hand after removing the plugs, have someone visually check to ensure all the pistons are coming up and down as the crank is turned. If one or more piston is not moving, you blew the engine. If they are, proceed with a compression test on each cylinder.