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The Sound of Excellence since 1981

Catalytic Converters

Since 1986, car manufacturers have been required by law to fit all new passenger vehicles with Catalytic Converters.

The Catalytic Converter is a pollution control device that transforms the pollutants such as carbon monoxide from your vehicle into less toxic substances with the help of oxidation and reduction.  Vehicles emit hydrocarbons, carbon monoxide, and nitrogen oxides into the atmosphere when petrol and diesel are burnt.  The Catalytic Converter is designed to reduce engine emission levels to meet an acceptable standard both for the environment and peoples health.  When operating in the right environment of high heat and correct air/fuel mixtures the catalyst forces a chemical reaction reducing toxic gases to less harmful ones.  The Catalytic Converter transforms carbon monoxide and hydrocarbons into carbon dioxide and water components with the Converter also breaking down the harmful nitrogen dioxide into nitrogen and oxygen.  

A Catalytic Converter Should Never Fail. If It Does, then there is an underlying problem that must be addressed or your new Catalytic Converter will also fail!

If your catalytic converter needs replacing, one of the problems below most likely contributed to its failure:

Engine requires servicing

A number of problems could occur to the catalytic converter as the result of an engine that is out of tune. Any time an engine is operating outside proper specifications, unnecessary wear and damage may be caused to the catalytic converter as well as the engine itself.  Any of these conditions could lead to a catalytic converter failure or worse.

Any of these conditions could lead to a catalytic converter failure or worse,

  • an incorrect air/fuel mixture
  • incorrect timing
  • misfiring spark plugs.  Spark plugs that do not fire or misfire cause unburned fuel to enter the exhaust system.  The unburned fuel ignites inside the converter and could result in a partial or complete meltdown of the catalyst.  Spark plug and spark plug wires should be checked regularly and replaced if damaged or if wires are worn or cracked.
Excess Fuel Entering Exhaust

Fuel is meant to burn in the combustion chamber only.  Any fuel that leaves the combustion chamber unburned will enter the exhaust system and light-off when it reaches the catalytic converter. This can over-heat the converter far above it’s normal operating conditions and cause a converter meltdown.

The possible causes are can be,

  • incorrect fuel mixture,
  • incorrect timing,
  • worn spark plugs,
  • a faulty oxygen sensor,
  • sticking fuel float,
  • faulty fuel injector,
  • malfunctioning check valve.
Oil or Coolant Entering Exhaust

Oil or coolant entering the exhaust system can block the air passages by creating heavy carbon (soot) that coats the pores of the catalyst.

These heavy carbon deposits create two problems.

  • the carbon deposits prevent the catalytic converter from reducing harmful emissions in the exhaust flow.
  • the carbon deposits clog the pores in the catalyst blocking it, increasing backpressure and causing heat and exhaust to back up into the engine compartment. Your engine may actually draw burnt exhaust gases back into the combustion chamber and dilute the efficiency of the next burn cycle. The result is a loss of power and overheated engine components.

Possible causes are,

  • worn piston rings,
  • faulty valve seals,
  • failed gaskets
  • warped engine components.
Oxygen Sensor Not Functioning Properly

An oxygen sensor failure can lead to incorrect readings of exhaust gases. The faulty sensor can cause a too rich or too lean condition. Too rich and the catalyst can meltdown, too lean and the converter is unable to convert the hydrocarbons into safe elements. Some of the manufacturers recommend the replacement of oxygen sensors every 80,000 kilometres.

Road Damage or Broken Exhaust Hangers

The catalyst inside a catalytic converter is made from a lightweight, thin-walled, fragile material that looks similar to honeycomb with an insulation mat protecting it. This mat holds the catalyst in place and provides some protection against damage. However, a rock or road debris striking the converter, improper or broken exhaust hangers can cause the catalyst to break. Once the catalyst is broken, the broken pieces become loose, rattle around and break up into smaller pieces. Flow in interrupted and back pressure in the exhaust system increases. This leads to heat build-up and loss of power.

Some of the possible causes of a broken catalyst are,

  • road debris striking the converter,
  • coming down off a kerb heavily,
  • loose or broken hangers,
  • potholes,
  • off-road driving.
Incorrect or Bad Batch of Fuel

Sadly not all fuels are created equal.  Some fuels can be contaminated with water, bacteria, fungi or any other foreign matter which all have the potential to damage a Catalytic Converter, or worse.  If you suspect contaminated fuel, do not drive your vehicle and call us immediately.

Catalytic Converters do carry a manufacturer warranty against faulty manufacturing processes, however, there is no warranty when they fail because of external damage or fail because of a vehicle engine fault such as those described above. This is why a well maintained and regularly serviced vehicle is so important. At Genie Exhaust our qualified and licensed staff can advise you on a proper maintenance schedule for you vehicle to keep it running at its most efficient.

contact us

(08) 9330 6900
30 Shields Cres., Booragoon WA 6154
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