What to Do If the Vehicle Fails the Emission Test?
2 Answers
If a vehicle fails the annual emission test, it is recommended to replace or clean the spark plugs, oxygen sensor, catalytic converter, and carburetor. Below is additional information on factors that may cause excessive emissions: Poor Quality Gasoline: Using low-quality gasoline may result in excessive vehicle emissions. Malfunctioning Exhaust Gas Recirculation System: If the exhaust gas recirculation system is not functioning properly, faulty input signal sensors can lead to an overly lean air-fuel mixture. Inaccurate Ignition Timing: Misfires or insufficient ignition energy in the ignition system can cause incomplete combustion of the air-fuel mixture. Low Cylinder Pressure: An excessively high engine operating temperature can be checked by observing the engine temperature on the diagnostic tool.
When my car fails the annual emission test, I prioritize checking if the catalytic converter is clogged. Cleaning carbon deposits from it often resolves the issue. A faulty oxygen sensor can also cause inaccurate fuel injection and excessive exhaust emissions, so replacing it is recommended. Additionally, worn spark plugs and a dirty air filter can affect combustion. I've tried cleaning fuel injectors and using fuel additives while driving on highways—simple DIY methods that can help. For cost control, getting a comprehensive diagnosis at a reputable auto repair shop, though more expensive, avoids repeated hassles. Regular maintenance includes avoiding low-quality fuel and occasionally revving the engine to clear carbon buildup. The car is a travel companion; neglecting repairs not only leads to test failure but may also result in fines or safety risks. Excessive engine carbon buildup increases noise and reduces driving comfort. My last repair cost 600 yuan, and now with emissions compliant, I feel much more at ease.
