The engine cranks but wont start

The oxygen sensor will not prevent the engine from starting. What could happen, in very rare instances, is the wiring harness to it could fall down onto hot exhaust parts or a sharp metal bracket, and the heater wire could become grounded. That would cause a fuse to blow that also supplies current to the fuel injectors and ignition coil.

Start by measuring the voltage on the feed wire to the ignition coil, any injector, or either small wire on the back of the alternator. You should find 12 volts there for one second after turning on the ignition switch, then again during engine cranking. If you never see voltage there, check the fuses and the automatic shutdown (ASD) relay. If you find voltage for that first one second but not during cranking, suspect the crankshaft position sensor or the camshaft position sensor.