What are two symptoms of a failed catalytic converter?
Two common symptoms of a failed catalytic converter are a check engine light and reduced engine performance.
When a catalytic converter stops functioning properly, it can trigger emissions-related diagnostic trouble codes and cause the engine to run less smoothly, sometimes accompanied by a sulfur odor or other exhaust anomalies. Here are the two most frequently reported signs to watch for.
Below are the two most common symptoms that indicate a catalytic converter may be failing:
- Check engine light with codes such as P0420 or P0430, signaling reduced catalyst efficiency.
- Decreased engine performance, including slower acceleration and lower fuel economy.
If you notice either symptom, have your vehicle inspected by a qualified mechanic to confirm whether the catalytic converter is at fault and to discuss repair options.
What to Expect During an Inspection
Diagnostic steps to verify a catalytic converter issue
A technician typically starts with an OBD-II scan to retrieve fault codes, then checks for exhaust leaks, tests catalyst temperature, and may perform a backpressure test to determine if the converter is clogged or damaged.
Correctly identifying a failed catalytic converter helps avoid unnecessary repairs and ensures the vehicle remains compliant with emissions standards.
Summary
In short, the most common signs of a failing catalytic converter are a illuminated check engine light with related codes and a noticeable drop in engine performance. Prompt diagnostic testing and professional evaluation are essential to confirm the cause and decide on repair or replacement.
