How are nitrogen oxides produced in automobile exhaust?

[DiMiguel]

They are mainly generated in the cylinder of an internal combustion engine, and the emission of nitrogen oxides depends on factors such as combustion temperature, time, and air-fuel ratio. The primary cause of nitrogen oxide formation is a high-temperature, oxygen-rich environment, such as carbon deposits in the combustion chamber. Automobile exhaust nitrogen oxides are produced in the following types of malfunctions: 1. Dirty air filter: Leads to less air and a richer mixture. 2. Insufficient fuel injection pressure or excessive injector nozzle gap: Results in poor atomization and a richer mixture. 3. ECU malfunction: Incorrect calculations leading to improper fuel injection adjustment, caused by faults in the oxygen sensor or air flow sensor. 4. Ignition system failure: Issues with the ignition coil, distributor, or spark plug (gap too large or too small, poor ignition), excessive carbon deposits on the spark plug. 5. Insufficient cylinder pressure: Excessive gap between piston rings and cylinder leading to leaks; loose spark plug bolts causing leaks; aging or damaged cylinder gasket resulting in leaks.