Why Do I Need to Change My Catalytic Converter?

Catalytic converters change harmful emissions into harmless gas, and they need to be replaced only if they become clogged or otherwise damaged and can’t function properly. They’re expensive to replace, so they aren’t considered a regular maintenance item. A damaged “cat” should trigger a Check Engine light. Signs of damage include sluggish acceleration, the smell of sulfur or rotten eggs from the exhaust, and excessive heat under the vehicle. Some of those symptoms can be caused by other parts of the emissions system, so a mechanic should check the entire system before replacing the converter.