Air Injection System: Description

This system adds a controlled amount of air to exhaust gases, assisting reduction of Carbon Monoxide (CO) and Hydrocarbon (HC) emissions. The system is designed so that air injection will not interfere with the ability of the EGR system to control NOx emissions. Air is injected at exhaust manifold during cold start until closed loop mode is achieved.

In closed loop mode, air supply is diverted downstream until an open loop idle condition takes place. Downstream, the air supply will assist oxidation process in catalyst but not interfere with EGR. The air injection system consist of air pump, air control valve, (either diverter valve, relief valve and/or switch/relief valve), vacuum solenoid or Coolant Vacuum Switch Cold Open (CVSCO), hoses, check valve(s) and injection tubes.