It was a story.
Probably got a free beer for the story.
A cat reduces the amount of CO that is emitted out the tailpipe. But it is never to zero. There is more than enough bad gas remaining to do the job (compared to a vehicle that does not have the device.)
Any carbon based material(paper, plastic, rubber, gas, oil, wood, tobacco, dope) all give off Carbon Monoxide.
Chemical fact you can confirm with a chemistry teacher(trouble with asking a teacher is that they will probably ask you to figure out the Molar volume of burning 20 grams of substance X (this was slide rule calculations) and chemical formulations.How long would it take to kill yourself in a car with a catalytic converter?
no, that wasnt the reason. cabon monoxide will kill you, even if you drive your car into a garage and then shut the car off, it could be deadly...its serious sht