What does invalid exhaust emission test mean?

[StHarley]

Invalid exhaust emission test refers to the mandatory test during the annual vehicle inspection. If the exhaust emission indicators fail to meet the standards, it is considered an invalid test. Vehicle owners should take this seriously and address the issue promptly. If the vehicle fails the retest for excessive emissions (non-compliance), penalties will be imposed. Introduction to vehicle inspection tips: Clean the throttle once before the inspection; Use 97-octane gasoline in advance. Higher-grade gasoline produces less pollution. If ethanol-blended gasoline is available, it is even better, as it contains 10% ethanol, which can reduce exhaust emissions by 10%; On the way to the inspection station, increase the engine speed. Due to urban traffic congestion, frequent stops and starts lead to incomplete combustion, resulting in pollutants adhering to the surface of the catalytic converter. Higher engine speeds produce the lowest emissions, and the high-speed airflow can also flush away deposits on the catalytic converter; After the exterior inspection, rev the engine hard. Taking a cold vehicle for the inspection is unwise. The reason is simple: the optimal working temperature of the 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 the inspection can quickly raise the catalytic converter's temperature above 400 degrees and maintain it for a while; If you suspect your vehicle has issues, you can remove the air filter or spray a small amount of water on it; Replace the catalytic converter if it is severely aged or ineffective. If the catalytic converter is poisoned, purchase a catalytic converter cleaner from the auto parts market and perform a cleaning maintenance on the engine. After maintenance, the exhaust emissions should pass the annual inspection. Notes: If a vehicle fails a random exhaust emission test, the traffic police will temporarily confiscate the vehicle's registration certificate. The owner must carry out repairs and rectifications within 7 days and can only retrieve the registration certificate upon presenting a retest pass certificate. No additional fees are required for the retest. Article 90: If a motor vehicle driver violates the road traffic safety laws or regulations regarding road traffic rules, a warning or a fine ranging from 20 to 200 yuan shall be imposed. If other provisions of this law stipulate otherwise, those provisions shall prevail. Article 95: If a motor vehicle driven on the road does not display a license plate, inspection compliance label, insurance label, or if the driver fails to carry the vehicle registration certificate or driving license, the traffic management department of the public security organ shall detain the vehicle, notify the party to provide the corresponding documents or labels or complete the necessary procedures, and may impose penalties in accordance with Article 90 of this law.