What Causes a Vehicle to Fail Emission Standards?
1 Answers
High sulfur and phosphorus content in gasoline can form chemical complexes on the surface of the oxygen sensor and the three-way catalytic converter; congested urban roads, frequent vehicle starts and stops, and idling lead to incomplete combustion, with byproducts adhering to the surface of the three-way catalytic converter; engine carbon deposits and particulate matter can clog the three-way catalytic converter, which are the primary reasons for a vehicle failing emission standards. Below are solutions to address emission failures: 1. Shift to 4th gear and drive at 5th gear speed with wide-open throttle for several dozen kilometers. Principle: Congested urban roads with frequent stops and starts result in incomplete combustion, producing pollutants that adhere to the three-way catalytic converter. At high RPMs, gasoline combustion emits the lowest levels of pollutants, and high-speed airflow can also flush away deposits on the three-way catalytic converter. 2. Keep the engine warm and idling without shutting it off. Before inspection, rev the engine in neutral for 3-5 minutes. Principle: Testing a cold vehicle is unwise. The reason is simple—the optimal operating temperature for the three-way catalytic converter is between 400 to 800 degrees Celsius, and it takes a long time for a cold engine to reach 400 degrees. Revving the engine for a few minutes before testing can rapidly raise the three-way catalytic converter's temperature above 400 degrees and maintain it for a period. 3. Regularly clean the three-way catalytic converter. Principle: Chinese gasoline has high sulfur and phosphorus content, forming chemical complexes on the oxygen sensor and three-way catalytic converter surfaces. Carbon buildup in the fuel system and intake tract, as well as particulate matter, can contaminate the three-way catalytic converter. This leads to restricted exhaust flow, increased backpressure, higher fuel consumption, reduced power, and diminished or even failed purification function of the three-way catalytic converter. In severe cases, it can clog the converter, potentially causing vehicle self-ignition.
