Air Injection System: Notes

Air injection system helps reduce hydrocarbon (HC), carbon monoxide (CO) and oxides of nitrogen (NOx) exhaust emissions by injecting air into the exhaust system. The induction of additional air promotes further oxidation (combustion) of unburned and partially burned exhaust gases. During cold engine operation, air is injected into exhaust manifold. This quickly warms up catalytic converter and oxygen sensor. When vehicle warms up, air is diverted to atmosphere or to the catalytic converter. See CATALYTIC CONVERTER.