What's the matter with excessive emissions?

The emission exceeds the standard, so this situation shows that the vehicle exhaust emission is unqualified, and the reasons for the unqualified exhaust emission are probably as follows.

First, excessive carbon deposition in vehicle engines leads to unqualified exhaust emissions. In this case, it is suggested to clean the three-way catalyst with carbon deposit at the throttle inlet. Add some premium gasoline, or fuel treasure.

Second, the three-way catalytic converter fails or is damaged. In this case, a new three-way catalytic converter needs to be replaced.

Third, the emission caused by engine oil combustion is unqualified, which requires overhaul.