Can I drive car without o2 sensor

Not a good idea. The upstream oxygen sensor is how the computer maintains the proper air to fuel mixture so the engine will run correctly. Without a signal from the upstream oxygen sensor the check engine light will be on constantly and the computer will go into default mode. You won't pass emissions inspection either. Hope that helps! Jim

However, to address the question of can you drive it, I would say yes. Your fuel mileage may suffer a little, but for the most part I don't think you'll even notice it apart from the engine light being on. There is no emissions testing where I live and I've driven cars with engine lights on (due to O2 sensors) for years at a timewith no problem.