N S

Thanks in advance.

Background:

- 1998 Honda Civic, manual transmission, 155k mi

- New fuel filter installed 2 months ago

- For about 2 months the check engine light has been on, rough idle. I ran the code and it came back with a faulty O2 sensor, heater (bank 1). I have not yet replaced the O2 sensor

- 2 weeks ago the power door lock switch stopped working (it works immidiately after driving the vehicle, but not after the car has been sitting for a while).

Problem:
I drove the vehicle to work in the morning, drove it to lunch in the afternoon with no trouble. Went to drive it home and it wouldn't start. Gas tank says there is just under a 1/4 tank left. I did try and jump it but it still wouldn't start (battery is less than a year old).

I don't think its a bad injector or spark plug as they would all have to be bad for the vehicle not to turn over. So I'm thinking its either fuel pump or distributor? How can I verify the fuel pump is working?

Any other items you would check?