DEF injector | T420858

Diesel Exhaust Fluid (DEF) Injector T420858 is a key component in the SCR (Selective Catalytic Reduction) aftertreatment system used to treat exhaust gas downstream of the engine. The injector is used to inject small quantities of diesel exhaust fluid (DEF) into the exhaust upstream of a catalyst, where it vaporizes and decomposes to form ammonia and carbon dioxide. The ammonia (NH3) is the desired compound which in conjunction to the SCR catalyst, converts the NOx to harmless nitrogen (N2) and water (H2O). The purpose of the SCR system is to reduce levels of NOx (oxides of nitrogen emitted from engines) that are harmful to our health and the environment.