Your vehicle’s catalytic converter is a small, oval-shaped chamber packed with materials such as platinum and/or palladium in a honeycomb-type design that sits ahead of the muffler in its exhaust system to ensure as much exhaust gas as possible passes over these metals, so that they can be converted into less harmful emissions before exiting the tail pipe. The converters placement can make it susceptible to failure from contaminants when other systems aren’t working right under the hood.
Catalytic converter failure can be a pain to fix. This essential emissions system component can sap miles per gallon and drive up your fuel consumption as it gradually loses efficiency and impacts your engine’s power production.
Common Causes for Converter Failure
1. Unburned Fuel
Heat can be damaging to almost any engine component, so it’s no surprise that it’s one of the most common causes of catalytic converter failure. Engine exhaust is already quite hot, so when you add in a contaminant like unburned fuel, which can find its way into the exhaust system when your motor is running too rich, you compound the effect, as that fuel typically ends up burning inside the converter itself. This can damage or even melt the honeycomb structure that is required for the catalyst metals to do their job, leading to a blockage and restriction in exhaust flow. If your engine is misfiring or if you see a warning code for a bad oxygen sensor, it’s a good idea to take care of the problem before it can lead to catalytic converter failure.
2. Coolant Leaks
Coolant leaking into your engine’s combustion chamber is a serious problem that can eventually do significant damage to your motor. A slow leak, however — say, from a bad head gasket — can also send enough coolant back through the exhaust system over time to clog your catalytic converter and contaminate the materials used inside of it until they are no longer effective. If you notice coolant disappearing from your engine’s reservoir or see white smoke in your exhaust, then that’s a sign of a bad head gasket, which should be corrected immediately.