Bad Catalytic Converter? – How to Know When

The most important part of your vehicle’s exhaust system is its catalytic converter.  Why?  Because it’s purpose is to reduce smog and toxic tailpipe discharges by “converting” hydrocarbons and carbon monoxide into harmless nitrogen.


New laws were implemented in 1968 mandating a reduction of auto emissions in the U.S., thus making catalytic converters an integral part of all new vehicles.  They’re now utilized in virtually every automobile world wide.  Since catalytic converters can’t operate in the presence of lead, the introduction of catalytic converters also ended production of leaded gasoline.

The byproducts of a vehicle engine are:

  • Water
  • Nitrogen (only some)
  • Carbon dioxide

These molecules are similar to the chemical output of animals. In reality however, the internal combustion process within an engine has never been 100% effective because it creates leftover unburned hydrocarbons.

Prior to 1960, these emissions were just permitted to be set free into the air…but this was later determined to be a public environmental health danger.

If a catalytic converter is attached to the tailpipe of a vehicle, it rapidly dissolves a very large percentage of the leftover unburnt hydrocarbons, and the result is a much cleaner emission. But, because the catalytic converter needs to operate at a high speed to catch the unburnt hydrocarbons before it goes out of the tailpipe, this now puts a limit on how effective the oxidation procedure can be.

Carbon monoxide emissions of cars and trucks have become much cleaner over the past several years…because catalytic converters have advanced tremendously due to technology advances. The  real challenge however, has been the reduction of CO2 (carbon dioxide) emissions.  The primary reason is because carbon dioxide cannot be dissolved into something less harmful. It’s an acknowledged greenhouse gas and it contributes to global warming.

Catalytic converters in consumer vehicles operate at a high temperature of around 750 degrees F or 400 degrees C.  Industrial use catalytic converters can often be larger than those utilized in consumer vehicles and also run at much higher temps.

Here are a few standard components of catalytic converters:

1) Heat exchanger
2) Catalytic bed – this takes the form of either a honeycombed ceramic or ceramic beads concealed in the catalyst.
3) A line burner

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