How to Solve Excessive NO Emissions?
2 Answers
Excessive NO emissions can be addressed by: first inspecting the three-way catalytic converter to ensure it is functioning properly, then checking if the EGR valve is stuck. NO refers to nitrogen oxides, and the reasons for excessive emissions are: 1. The air-fuel mixture in the engine combustion chamber is too rich, usually caused by incomplete combustion; 2. Severe carbon deposits, mainly in the intake system and engine combustion chamber; 3. The combustion chamber temperature is too high with sufficient oxygen supply. NO is the general term for nitrogen oxides, which are gases formed by the chemical reaction between nitrogen and oxygen. The primary component of the well-known PM2.5 is nitrogen oxides. Compression-ignition engines primarily emit NO, while spark-ignition engines emit CO, HC, and NO. For gasoline engines, excessive NOx emissions are relatively rare.
Last time my NO exceeded the standard, it was detected during the annual inspection. I immediately checked the exhaust system, focusing on the catalytic converter filter screen, which tends to clog when it ages. Then I checked the oxygen sensor, cleaning or replacing it if dirty. I usually use 95-octane gasoline, which is cleaner than 92-octane and reduces pollution. If the exceedance is severe, the catalytic converter might need replacement—costly but thorough. I always make it a habit to regularly clean the fuel system and throttle body to prevent carbon buildup that leads to poor emissions. Don’t delay if emissions exceed standards—driving pollutes the air, risks fines, and harms environmental safety. I recommend taking short highway trips weekly to clear carbon deposits and having the mechanic thoroughly inspect emission components during maintenance to ensure everything is in order.
