What does it mean when the engine exhaust system warning light comes on?
1 Answers
When the engine exhaust system warning light comes on, it indicates that the three-way catalytic converter in the car's exhaust pipe has failed. At this point, the engine will limit power output, causing the vehicle's exhaust emissions to exceed standards, which can affect annual inspections. The exhaust pipe of a car contains a three-way catalytic converter, which is installed in the front section of the exhaust pipe. The three-way catalytic converter is used to purify exhaust gases. After the engine's exhaust gases pass through the three-way catalytic converter, the levels of harmful and toxic substances are reduced. There are oxygen sensors located before and after the three-way catalytic converter. The front oxygen sensor is used to measure the oxygen content in the exhaust gases. This sensor sends data to the ECU, which adjusts the engine's air-fuel ratio based on this data and other inputs. The rear oxygen sensor, located after the three-way catalytic converter, is primarily used to detect whether the catalytic converter has failed. If the data sent to the ECU by the front and rear oxygen sensors are the same, it indicates that the three-way catalytic converter has failed, and the engine warning light on the car's dashboard will illuminate.
