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 passive after-treatment device designed to reduce engine-out emission levels to meet an acceptable standard. Together with the emissions of Platinum, Palladium and Rhodium and a Ceria based wash coat, packed into a stainless steel housing. When placed in the right environment of heat (400˚C) and proper air/fuel mixture the catalyst forces a chemical reaction reducing toxic gases to less harmful ones.

A Catalytic Converter Should Never Fail. If It Does, Then There Is A Problem!

Just replacing the converter will not fix the problem.

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

Engine Tune-Up Required

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. The damage is often the result of an incorrect air/fuel mixture, incorrect timing, or misfiring spark plugs. Any of these conditions could lead to a catalytic converter failure or worse.

Excess Fuel Entering Exhaust

The fuel that powers your vehicle is meat 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 super-heat the converter far above normal operating conditions and causes a converter meltdown. Possible causes are an incorrect fuel mixture, incorrect timing, corroded spark plugs, a faulty oxygen sensor, sticking float, faulty fuel injector or a malfunctioning check valve.

Oil or Antifreeze Entering Exhaust

Oil or antifreeze entering the exhaust system can block the air passages by creating heavy carbon soot that coats the catalyst. These heavy carbon deposits create two problems. First, the carbon deposits prevent the catalytic converter from reducing harmful emissions in the exhaust flow. Second, the carbon deposits clog the pores in the catalyst and block exhaust, 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 or warped engine components.

Deteriorated Spark Plug or Spark Plug Wires

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.

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 Hangers

The catalyst inside a catalytic converter is made from a lightweight, thin-walled, fragile material. A dense insulation mat protects it. This mat holds the catalyst in place and provides moderate protection against damage. However, a rock or road debris striking the converter or improper  or a broken exhaust system hanger can cause a catalyst fracture. Once the catalyst is fractured, 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. Possible causes of a catalyst fracture are road debris striking the converter, loose or broken hangers, potholes or off-road driving.

Talk to the helpful staff at Genie Exhaust for which converter will best suit your car and application. We can also fix the underlying problems.

Genie Exhausts can supply and fit:

  • Non-genuine replacements
  • Magnaflow high performance converters
  • Race Catts (for high performance and racing applications)
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