O2 Sensor Replacement
 

I replaced the O2 Sensor today on the FD because it would pop CEL code 15 and/or code 17. The codes normally appeared when driving at a constant 55-65MPH. It was a little tough to remove the old one but it came out. I had to come from underneath the car and use a 22mm combo wrench to get enough purchase on the sensor. Overall, the process went smoothly taking roughly 1.5hrs, not accounting to cool the engine & exhaust after driving up car ramps. A brief test drive revealed no problems and at least for now, no CEL (knocking on some wood)!

When replacing the O2 Sensor, I ordered it thru Oxygen Sensor Depot. That is an evolution from an older site (cited in the FAQ), oxygensensors.com. The replacement is a Walker Products sensor and it comes with the wire connector. That is a huge plus for plug-and-play! I dislike having to cut old wire then splice in a new one. This replacement sensor has a thick braided blue insulator and has the proper length cable to run from the downpipe to the plug behind the UIM.

Here are some photos of the new vs. old O2 Sensor:

https://cimg7.ibsrv.net/gimg/www.rx7...57b6b9ba82.jpg

New O2 Sensor on Left vs Old O2 Sensor on Right

https://cimg9.ibsrv.net/gimg/www.rx7...7427fa5016.jpg

Old sensor and dried copper anti-seize.

https://cimg0.ibsrv.net/gimg/www.rx7...b8a81f26ff.jpg

Small amount of soot by threads.

Good info. How were you pulling the CEL's while driving?

Rockauto sells the OEM NGK/NTK oxygen sensor with correct plug also. The Walker part you got looks good, too.

Rock Auto...noted for future reference.

Thanks for finding the post informative. The codes were checked once parked.

Had a chance to drive the FD over the weekend. Put some highway miles on her and kept it under Warp 1. Not once did the CEL come on so it looks like the problem is solved!