An essential part of your vehicle's pollution-control system One of the key components of your vehicle's anti-pollution system is the catalytic converter. It is designed to eliminate a major portion of your engine's emissions by converting them to water and relatively harmless gases.

How the converter works

The catalytic converter is an extremely sophisticated piece of engineering designed to take advantage of basic physical chemistry. It consists of one or more ceramic honeycombs coated with a microscopic film of precious metals. This film traps the hot exhaust gases and breaks them down in a high-temperature chemical reaction. As a result, the exhaust that comes out of the tail pipe is much less harmful to the environment. These ceramic honeycombs are held in a sealed container and protected by insulation.

A very reliable part

A catalytic converter contains no moving parts to wear down or get broken. The catalytic converter is one of the most durable and reliable parts in an entire motor vehicle system. In theory, it should last as long as your vehicle. However, it may sometimes have to be replaced. Unless the converter has sustained direct physical damage, its failure is usually the sign of an engine problem that should be corrected to prevent the new converter from breaking down within a relatively short period of time.




CAUSES OF CATALYTIC CONVERTER BREAKDOWN

When a catalytic converter needs to be replaced, one or more of the following problems may be at fault.

	Out-of-tune engine A great many catalytic converter breakdowns are due to an engine that badly needs a tune-up. Another common problem is an incorrect air-fuel mixture, or dirty spark plugs, worn-out wires or a de-synchronized timing system. All these prevents the fuel from burning completely in the cylinder. In such cases, fuel may leak into the exhaust system and burn on contact with the catalytic converter. As a result, the part will overheat, causing the catalytic ceramic to melt.
	Presence of fuel in the exhaust line Other problems may also arise due to gasoline in the exhaust line caused by defective fuel injectors, or a malfunctioning check valve. An oxygen detector failure can also affect the air-fuel mixture, which can be too rich or too poor. If it is too rich, the catalytic converter may melt. However, if the mixture is too poor, it may not be possible for the converter to convert hydrocarbons into harmless compounds.
	Highway impacts or broken mountings The inside a catalytic converter is made of a lightweight, thin, highly fragile material. A thick insulating blanket provides some moderate protection against damage. However, the impact of rocks or debris thrown up against the converter, or shock from potholes or off-road driving, or even a broken mounting can all cause the converter to break. Once the catalytic ceramic is damaged, broken pieces rattle against each other and shatter. The exhaust flow is interrupted, and this leads to a pressure increase at the intake causing loss of power and overheating.

HOW TO DETECT A BROKEN CONVERTER:

	Converter meltdown/ Carbon deposits The catalytic converter may heat up until the internal temperature is higher than the melting point of the catalytic ceramic, and at this point it will begin to melt. At such temperatures the catalytic converter will be red hot. If it has time to cool, it will show discolorations that indicate what has happened inside.
	Breakage Look for signs of shock or impacts on the surface of the catalytic converter, as well as symptoms of overheating.