Can I use generic CO2 sensor, like these?

[madspeed50]

the rear o2 sensor can be cleaned. if its all sooted up and the holes or slots are plugged it will give an incorrect reading. it will not affect anything except trigger a CEL if out of range. I wouldnt fuss with the front sensor, as its the one that does all the work right?

Yep, sent from my rooted, rommed Galaxy Nexus....