Hello
I got my daughter this 2006 Honda Civic Hybrid and the check engine light came on. I scanned it and the code that was thrown is P0420 I have changed the Upstream O2 Sensor cleared the code and it came back. In looking at the live data I noticed this reading

O2S B1S12--B2S------?
The O2B1 S2 (v) is running 0.74 to 0.48

Any Idea where to go from here.

Thanks

The cat is probably bad

I have seen an article about the PCM Software needing to be updated. As, to me the one sensor is not being read at all and sensor 2 getting a reading. Could aftermarket sensors not be compatible with the PCM software. I may getting myself in trouble with the live data as I really don't know what I am looking at for sure.

aftermarket sensors can definitely give you problems
do you still have the original sensor?

I have the sensor that I took out I do not know if it is the original it looks the same as the new one. The new one that I put in is a Denso Part number 234-9063.