My car's been misfiring for the last couple weeks and I cant figure out what it is. Its throwing a po300 code (random misfire) and a po173 code (fuel related?). Cant figure out for the life of me what's causing it to misfire. Im thinking that its something injector related since its coming up as a fuel problem or even a fuel pump. Any ideas? I replaced the fuel filter with a 300zx filter but that had no effect on the misfire.

 

Use this to narrow it down.

http://boredmder.com/ecucodes/