Check engine light turns on
Usually, an illuminated check engine light is the first and only sign of a bad catalytic converter. When the light pops on, your car's engine control module (ECM) will also store a diagnostic trouble code (often a P0420 code) in its memory.
What are three signs of a bad catalytic converter?
Among the symptoms of a bad catalytic converter are:
- Sluggish engine performance.
- Reduced acceleration.
- Dark exhaust smoke.
- The smell of sulfur or rotten eggs from the exhaust.
- Excessive heat under the vehicle.
Can a bad catalytic converter not throw a code?
It is possible to clog the cat and not throw a code. sensor and see if the power is restored.
