can someone still kill themselves with running car in garage w/modern catalytic?

[vash]

figure i would ask here. wife's chem professor said that a new car, with modern catalytic convertor is so efficient you cannot die in a closed garage. any bit of CO would kill you right?

just askin...no plans.

[masraum]

Hmm, I would think that you still can, but it would take longer.

Probably not so much with a Prius.

[maxnine11]

I'll go try right now and get back to you later.
Maybe.

[Gogar]

Cliff, you've really had some interesting thread titles lately.

[LakeCleElum]

I know of a case where a gal started her diesel rabbit and ran a hose from tailpipe to the interior....Then she passed out drunk.....IN the morning, she just smelled like diesel exhaust....

[Mr_Wizard]

I think Mythbusters tested this.

[azasadny]

I don't believe the catalytic converter reduces the carbon monoxide...

[vash]

i thought a cat converts CO into CO2 + H2O?

[porsche4life]

Exactly... The motor is still burning the oxygen and increasing the CO in the room....

[azasadny]

Edited info from Wikipedia:

Catalyst poisoning occurs when the catalytic converter is exposed to exhaust containing substances that coat the working surfaces, encapsulating the catalyst so that it cannot contact and treat the exhaust. The most notable contaminant is lead, so vehicles equipped with catalytic converters can only be run on unleaded gasoline. Other common catalyst poisons include manganese primarily from the gasoline additive MMT, and silicon which can enter the exhaust stream if the engine has a leak allowing coolant into the combustion chamber. Phosphorus is another catalyst contaminant. Although phosphorus is no longer used in gasoline, it (and zinc, another low-level catalyst contaminant) was until recently widely used in engine oil antiwear additives such as ZDDP. Beginning in 2006, a rapid phaseout of ZDDP in engine oils was begun.

Depending on the contaminant, catalyst poisoning can sometimes be reversed by running the engine under a very heavy load for an extended period of time. The increased exhaust temperature can sometimes liquefy or sublimate the contaminant, removing it from the catalytic surface. However, removal of lead deposits in this manner is usually not possible due to lead's high boiling point.
Two-way

A two-way catalytic converter has two simultaneous tasks:

1. Oxidation of carbon monoxide to carbon dioxide: 2CO + O2 → 2CO2
2. Oxidation of unburnt hydrocarbons (unburnt and partially-burnt fuel) to carbon dioxide and water: CxH2x+2 + 2xO2 → xCO2 + 2xH2O (a combustion reaction)

This type of catalytic converter is widely used on diesel engines to reduce hydrocarbon and carbon monoxide emissions. They were also used on spark ignition (gasoline) engines in USA market automobiles through 1981, when the two-way converter's inability to control NOx led to its supersession by three-way converters.
[edit] Three-way

Since 1981, three-way catalytic converters have been used in vehicle emission control systems in North America and many other countries on roadgoing vehicles. A three-way catalytic converter has three simultaneous tasks:

1. Reduction of nitrogen oxides to nitrogen and oxygen: 2NOx → xO2 + N2
2. Oxidation of carbon monoxide to carbon dioxide: 2CO + O2 → 2CO2
3. Oxidation of unburnt hydrocarbons (HC) to carbon dioxide and water: CxH2x+2 + 2xO2 → xCO2 + 2xH2O

These three reactions occur most efficiently when the catalytic converter receives exhaust from an engine running slightly above the stoichiometric point. This is between 14.6 and 14.8 parts air to 1 part fuel, by weight, for gasoline. The ratio for LPG, natural gas and ethanol fuels is slightly different, requiring modified fuel system settings when using those fuels. Generally, engines fitted with 3-way catalytic converters are equipped with a computerised closed-loop feedback fuel injection system employing one or more oxygen sensors, though early in the deployment of 3-way converters, carburetors equipped for feedback mixture control were used. While a 3-way catalyst can be used in an open-loop system, NOx reduction efficiency is low. Within a narrow fuel/air ratio band surrounding stoichiometry, conversion of all three pollutants is nearly complete. However, outside of that band, conversion efficiency falls off very rapidly. When there is more oxygen than required, then the system is said to be running lean, and the system is in oxidizing condition. In that case, the converter's two oxidizing reactions (oxidation of CO and hydrocarbons) are favoured, at the expense of the reducing reaction. When there is excessive fuel, then the engine is running rich. The reduction of NOx is favoured, at the expense of CO and HC oxidation.
[edit] Oxygen storage

Three-way catalytic converters can store oxygen from the exhaust gas stream, usually when the air fuel ratio goes lean[4]. When insufficient oxygen is available from the exhaust stream the stored oxygen is released and consumed. This happens either when oxygen derived from NOx reduction is unavailable or certain maneuvers such as hard acceleration enrich the mixture beyond the ability of the converter to compensate.
[edit] Unwanted reactions

Unwanted reactions can occur in the three-way catalyst, such as the formation of odiferous hydrogen sulfide and ammonia. Formation of each can be limited by modifications to the washcoat and precious metals used. It is difficult to eliminate these byproducts entirely.

[red-beard]

Modern cars do produce CO, when they are cold, running in "rich" mode. Once they warm up, they are pretty darn clean.

Can you kill yourself? Yep. CO2 is a smothering agent, displacing O2. It is possible to deplete the O2 enough to die. The ventless gas heaters I used to use had O2 depletion sensors to shut the gas off if the O2 in the room goes low.

CO will kill you, even without O2 depletion.

[legion]

It's like putting yourself in a sealed yourself in a room with another person. One of you will pass out first because both of you will are breathing and expelling CO2.

[TSNAPCRACKLEPOP]

if you locked me in the garage with a converter car overnight, i am sure my breath would kill the car by morning.

but, you could theoretically kill yourself in the garage with the car running...there are several different methods.

[1990C4S]

Try a 2-stroke lawnmower.

Someone I know regularly traps 'varmints' and then puts them on the tailpipe of the car to get rid of said varmint. The new Cadillac he drives won't kill a varmint. Too clean.

A carburetted car or a lawn-mower works.

[mattdavis11]

Didn't work for a guy I know, 2004 Infinity.

[p911dad]

I tested a new CO alarm by placing it close behind the exhaust on a late model Ford(almost new). The alarm did go off. Check the owner's manual, I think they still warn against running the car in a closed space.

[1990C4S]

Originally Posted by gmeteer

Check the owner's manual, I think they still warn against running the car in a closed space.

That's the lawyers, what do they know? The engineers probably do it. I do.

[vash]

hey, i have an old car, and a new car...and a gas tester.

i'll suss it out myself.

[Hugh R]

Very hard to do. The CO2 displacing O2 is what could do it. New cars don't put out much CO.

[Laneco]

Hmmm. Question...

If the CO2 is displacing the O2 - what would give out first? Would the car run out of O2 to support combustion or would YOU die first?

Not that I plan to test the theory at all, I'm just curious.

angela