Now whatever has been causing my problems has increased a thousand fold. Now the car wont start at all. First, I started it to go to the store, it ran unevenly for about 20 feet, then sputtered and died. It would not restart. I pushed it back and kept trying to get it to start. 9 times out of ten it would turn over and turn over without starting and then make a spitting sound when I stopped turning the key. A couple times it started but immediately sputtered and died. once it started and ran seemingly normal for a min but as soon as I put it in gear it sputtered and died. I have not since been able to get it to start.

Could a faulty o2 sensor cause the car to not run at all? Or am I looking at something in the fuel delivery (fuel pump, injectors, etc.)? And if so, how do I test these things when the engine won't run? I don't have the money to simply start replacing parts with the hope I'll guess right.