Yes! If the brick of a catalytic converter breaks away or comes loose, it can block the exhaust system. This can cause massive backpressure to form in the engine that in turn could harm your engine.
Introduced to Australian motor vehicles in 1986, catalytic converters were fitted to unleaded petrol vehicles to clean up the noxious exhaust gases produced during operation. The role of the catalytic converter is to control the harmful emissions from the combustion process by converting the Hydrocarbons (HC), Nitrogen Oxides (NOx) and Carbon Monoxide (CO) into Carbon Dioxide (CO2), Nitrogen (N2) and Water Vapour (H2O).

The catalytic converter is designed to last the lifetime of the vehicle, but this is not always the case. The premature failure of the catalytic converter could be attributed to poor tuning of the vehicle’s ignition, a lack of servicing at regular intervals, road impact damage, driving through deep water or using non-compatible fuels and additives. These conditions need to be avoided by the owner of the vehicle in order to ensure a healthy catalytic converter.
The most obvious reason for catalytic converter failure is a poorly tuned engine that discharges excess fuel and nitrous oxides into the catalytic converter, causing it to fail. In vehicles purchased after 2004 you may experience an engine light appearing on our dashboard.

The catalytic converter is designed to last the lifetime of the vehicle, but this is not always the case. The premature failure of the catalytic converter could be attributed to poor tuning of the vehicle’s ignition, a lack of servicing at regular intervals, road impact damage, driving through deep water or using non-compatible fuels and additives. These conditions need to be avoided by the owner of the vehicle in order to ensure a healthy catalytic converter.
No. All cars registered in QLD after 1986 are required to have a minimum of one catalytic converter by law. The penalty for removing a catalytic converter can be up to $10,000.
  • Ensure any engine or emission faults are rectified before replacing the catalytic converter. Failure to correct a pre-existing emissions problem could result in a damaged catalytic converter.
  • It is recommended to replace the oxygen sensor when the catalytic converter is replaced. For correct operation of the engine and catalytic converter, the vehicle must be fitted with an oxygen sensor. When combustion gases are flowing through the exhaust, they are picked up by the oxygen sensor and a signal is sent back to the ECU. This signal then helps to control the air/fuel mixture entering the combustion chambers for a better ‘burn’.
  • Always use new mountings, gaskets and bolts to avoid leakage or fitment issues. This will ensure the correct fitment first time around. Always recommend new studs, bolts and nuts when replacing any part of the exhaust system.
  • When replacing a catalytic converter, it is essential to examine the complete exhaust system from the manifold to the tail pipe for damage, corrosion or leaking/blowing. Repair or replace as required. A simple test is to have the vehicle running at idle whilst on the hoist. Use a shop rag to block the tail pipe (without burning your hand) and listen for any exhaust leaks in the system. Two people will be required for a closer inspection of any joins/pipes. The use of a vapour or smoke machine will accurately locate any exhaust leaks.
  • After replacing the catalytic converter, be sure to run the vehicle at 2500rpm until the electric fans kick in. Then run the vehicle for a further minute until the new catalytic converter temperature reaches 250°C to ensure it is lighting off and functioning properly.
  • Do not use exhaust sealant upstream of the catalytic converter. This can be a fatal move when working on the exhaust system. Sealants can contain ingredients that will harm the operation of the catalytic converter and also damage the oxygen sensor.
This all depends on the age of the car. From 1986 to 2002, most catalytic converters were 400 cpi, but this rose to 600 cpi in many cases in 2003 when Euro 3 was introduced. In 2008, cars were fitted with Euro 4 catalytic converters, and since then Euro 5 and Euro 6 emissions standards have also been introduced. Euro catalytic converters have more metal coating on the ceramic brick to burn off more hydro carbons, making them more expensive.