The smart car failed the environmental inspection.

Replace the spark plug and clean the throttle.

1, you can try to replace the spark plug, both old and new, as long as you clean the electrode points with sandpaper and adjust the gap; It is very important to adjust the ignition time and delay the ignition time, which will obviously reduce the NO content in the exhaust gas.

2, you can also use cleaning agent to clean the throttle, which may be too dirty, resulting in poor discharge; Or the quality of gasoline used is not good, resulting in insufficient combustion and too much waste gas. You can replace No.97 gasoline or No.97 ethanol gasoline.