your post is very confusing.
it won't start. That is what I would look at first. Why would you be looking at it not going into any gear if the engine won't start? Why do O2 sensors
and egr parts if the engine won't start?
If you removed all the spark plugs and couldn't rotate the crank, My first thought would be a seized engine. I don't know what you were wrenching on the flywheel to try and turn the engine but i would try to turn the crank using the bolt on the front crank pulley. If the engine doesn't rotate with all the spark plugs out while trying to rotate the crank using the crank pulley bolt (turning clockwise) Something is really stuck. Now you have to have all the spark plugs out. Not just the front ones. It could be possible that you have fluid filled up in a cylinder causing a hydrostatic lock. WARNING! it is possible that gasoline could fill up a cylinder causing a hydrostatic lock. If this is the case, after removing the spark plugs and cranking the engine would push gasoline out of the spark plug
hole under extreme pressure and any spark could ignite this fuel causing a fire. Rotate the engine by hand, ignition key off. Don't take any chances in case it is gas. If it is coolant it will just splash all over.
but if you cannot rotate the engine with all the spark plugs out you have an engine problem, why worry about not going into gear?