What to Do When NOx Levels Exceed Standards?

[StElliott]

First, inspect the three-way catalytic converter to check if it is functioning properly, then examine whether the EGR valve is stuck. NOx refers to nitrogen oxides, and the reasons for exceeding standards are: 1. The air-fuel mixture in the engine combustion chamber is too rich, usually caused by incomplete combustion; 2. Severe carbon buildup, with common locations including the intake system and engine combustion chamber; 3. Excessive combustion chamber temperature combined with sufficient oxygen. Additional relevant information is as follows: As one of the main sources of air pollution, vehicle exhaust contains a large amount of harmful substances, including carbon monoxide, nitrogen oxides, hydrocarbons, and solid suspended particles. PM2.5, which has become a major social concern, falls under the category of solid suspended particles.