[XorNot]

This is in theory not a problem: getting an oxygen sensor to 700 degrees if it's a tiny spec on a chip is not necessarily hard or would even require a lot of power.

But...oxygen concentration is essentially indepedent of CO2. We measure CO2 at part per million levels, whereas O2 is 20% of the air.

(In that context CO2 is surprisingly toxic given that 1000 ppm can impair mental acuity).

[coryrc]

> whereas O2 is 20% of the air.

The goal of a gasoline engine's sensor is to accurately and precisely measure the point where O2 concentration reaches zero, so ambient air levels are not quite as relevant.