* Insufficient catalytic activity: If the converter isn't working properly, it won't convert harmful emissions effectively. The sensors in the exhaust system will detect this and trigger the light.
* Clogged converter: A severely clogged catalytic converter restricts exhaust flow, causing increased backpressure. This is readily detected by the OBD system.
* Internal damage: Physical damage to the converter's internal structure can also cause it to malfunction and trigger the check engine light.
It's important to note that while a bad catalytic converter *can* cause the check engine light, it's not the only reason. Many other issues can also trigger it, so diagnosis by a mechanic is necessary to pinpoint the exact cause.
