Catalytic Converter Symptoms: 7 Warning Signs That Demand Fast Action Most drivers search for catalytic converter symptoms after noticing a check engine light, unusual exhaust smell, strange noise, reduced acceleration, or a change in fuel economy. The important point is that these signs do not automatically prove the catalytic converter has failed. A problem with the engine, fuel system, oxygen sensors, wiring, or exhaust can produce similar warnings. The most useful approach is therefore to treat a symptom as evidence that the emissions system needs attention—not as a diagnosis by itself. 7 Catalytic Converter Symptoms at a Glance The main warning signs include: Important: None of these signs alone proves…