THis is for EF9 SiR, with2 catalytic converter "O2" sensor, and 2 O2 sensors on manifold. I need info on this sensor, My halfcut came with it but nothing shows up on wiring diagrams I have for the Sir. Does anyone know anything about this. Its smaller than an O2 sensor, but its in the converter case at the output side of the core. Someone has to know something about this.

 

Its not an O2 sensor, its a cat temp sensor. You dont need it. Its is wired into a plug above the floor pan, its a single wire sensor and to avoid CELs you just earth it to some part of the body. It has no input to the ECU so even running with out it hooked up wont make any difference. cat temp sensors are on all JDM hondas.
Look on the gauge cluster in the top left corner, you will see a warning light, sort of rectangular in shape and with two squiggles rising from it, thats the light that will come on when the sensor is not hooked up. You can either earth the single wire or just remove that bulb if you plan using the SiR cluster.

 

OK, thank you so much, I have been pulling my hair out trying to figure out what it was. ODB2 cars have an O2 sensor there, so was wondering what the ****. And thanks anout the CEL tip for this because yes I am using the JDM cluster and ECU that came with this.