Nice one. Anyway three-way catalytic converters also convert NOx to N2 and O2. It would be quite bad if they wouldn't.
> You only get water vapour and carbon dioxide out.
No, you still get small amounts of the bad (acutely toxic) stuff too. This point is important - whether it's home cooking on gas, gas heating or ICEs running on unicorn farts, there will still be byproducts from imperfect burning. The only real way out is to turn off the fire.
