This may be due to the operation of the three-way catalytic converter. Below is the relevant information: 1. Function of the three-way catalytic converter: The three-way catalytic converter is the most important external purification device installed in the automobile exhaust system. It converts harmful gases such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) emitted from vehicle exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. 2. Causes of failure: At room temperature, the three-way catalytic converter does not possess catalytic capability. Its catalyst must be heated to a certain temperature to gain oxidation or reduction capability. Typically, the light-off temperature of the catalytic converter ranges between 250–350°C, and its normal operating temperature is generally between 400–800°C. During operation, the catalytic converter generates a significant amount of heat. The higher the load, the higher the oxidation temperature. When the temperature exceeds 1000°C, the catalyst coating inside will sinter and fail, and it also becomes highly prone to vehicle self-ignition accidents. Therefore, it is essential to control various factors that cause an increase in exhaust temperature, such as delayed ignition timing, incorrect ignition sequence, or misfiring. These can allow unburned fuel mixture to enter the catalytic converter, leading to excessively high exhaust temperatures and impairing the efficiency of the catalytic converter.
