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Speaker 1: Welcome to Brainstuff from house stuff works dot com where

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Speaker 1: smart happens. Hi. I'm Marshall Brain with today's question, how

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Speaker 1: do I know if my catalytic converter is failed? To

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Speaker 1: understand why a catalytic converter fails, you need to know

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Speaker 1: how it works. The catalytic converter is the part of

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Speaker 1: the automobile exhaust system that converts harmful compounds in the

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Speaker 1: exhaust into harmless compounds. It does this by using a catalyst,

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Speaker 1: which speeds up chemical reactions. The catalysts can take unburned

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Speaker 1: hydrocarbons in the exhaust stream and burn them. It can

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Speaker 1: turn carbon monoxide into carbon dioxide, and so on. The

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Speaker 1: thing that does this is a honeycomb piece of ceramic

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Speaker 1: with the catalysts embedded in it. And if you were

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Speaker 1: to ever look at this, the holes going through that

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Speaker 1: catalysts are very very small. So one of the easiest

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Speaker 1: way is for a catalytic converter to fail is for

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Speaker 1: it to become clogged. Often, the only way to tell

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Speaker 1: if your catalytic converter is plugged up is to remove

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Speaker 1: it and check for the change in engine performance, or

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Speaker 1: some mechanics temporarily remove the oxygen sensor from the exhaust

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Speaker 1: pipe ahead of the catalytic converter and see if that helps.

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Speaker 1: It opens up a big enough hole to lead exhaust

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Speaker 1: through if the converter is plugged up. Sometimes you can

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Speaker 1: tell that a converter is clogged because you don't go

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Speaker 1: any faster when you push on the gas pedal at

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Speaker 1: a certain point. Also, there's usually a noticeable dropping gas

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Speaker 1: mileage associated with a clogged converter. A partially clogged converter

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Speaker 1: often acts like an engine governor. A totally clogged converter

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Speaker 1: causes the engine to quit after a few minutes because

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Speaker 1: of all the increased exhaust back pressure. A catalytic converter

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Speaker 1: can also fail because of bad exhaust valves on the

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Speaker 1: engine or fouled plugs, which cause unburned fuel to overheat

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Speaker 1: the converter. A catalytic convert to relies on receiving the

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Speaker 1: proper mix of exhaust gases at the proper temperature. Any

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Speaker 1: additives or malfunctions that cause the mixture or the temperature

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Speaker 1: of the exhaust gases to change reduce the effectiveness and

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Speaker 1: the life of a catalytic converter. Letted gasoline and overuse

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Speaker 1: of Certain fuel additives can also shorten the life of

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Speaker 1: a catalytic converter by poisoning the catalyst. Here's a safety reminder,

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Speaker 1: do not park your car over tall grass or piles

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Speaker 1: of dry leaves. Your cars perfectly running catalytic converter gets

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Speaker 1: incredibly hot, hot enough to start fires. Do you have

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Speaker 1: any ideas or suggestions for this podcast? If so, please

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Speaker 1: send me an email at podcast at how stuff works

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Speaker 1: dot com. For more on this and thousands of other topics,

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Speaker 1: go to how stuff works dot com and be sure

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Speaker 1: to check out the brain stuff blog on the house

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Speaker 1: stuff works dot com home page.