How Do I Know When It’s Time to Replace My Catalytic Converter?

Catalytic converters, which convert pollutants into harmless gases, can be damaged by road debris, contaminated by engine oil or coolant, or become clogged and restrict exhaust flow. Among the signs of a bad catalytic converter are sluggish performance, dark exhaust smoke or the smell of rotten eggs in the exhaust. A misfiring spark plug, faulty oxygen sensor, or other fuel or emissions-related problem can cause a catalytic converter to overheat.