I thought I would give a quick guide to replacing the oxygen sensor on my 2007 Honda Fit Sport automatic. The check engine light came on at 80,000 miles so I borrowed a scan tool from my local Advance Auto. Plugging into the OBD port gave me a P2A00 code for the Bank 1 Sensor 1 oxygen sensor. I purchased the Denso oxygen sensor with harness for $180. You can probably find a AA discount code online somewhere. I also borrowed (free) the oxygen sensor removal tool from AA.

You can reach the electrical connection from the top of the engine. The YouTube video on oxygen sensor replacement with the white Honda Fit explains the connection well. I reached in from the passenger side of the engine to disconnect. It took a while to get this off. Look at the new harness connection to see how it disconnects. First disconnect the drivers side, then the passenger side of the clip connection.

Then I lifted up the Fit from the drivers side and put in safety stands. You can reach the oxygen sensor from underneath. It's on the back side of the engine when looking up. Using the borrowed offset tool and a long ratchet, the oxygen sensor came loose on the second try. I installed the new oxygen sensor medium tight strength. Then I reinstalled the electrical connection from up top. Passenger side first, then drivers side. That's it. I hope this helps someone.