The article discusses new technologies and research that automakers are conducting to reduce these emissions. The method of selective catalytic neutralization (SCR), which is the most advanced technology used to limit the amount of harmful nitrogen oxides in diesel vehicles, is analyzed, the necessary conditions for minimizing the amount of nitrogen oxide and chemical reactions are explained. The advantages and disadvantages of the SCR system in comparison with other technologies are considered, as well as the features of its adaptation to vehicles are discussed.