Pulsair Valve: Description and Operation

Fig. 26 Pulse air control (secondary air control) system schematic:

This system reduces HC and CO emissions during cold engine operation or deceleration by supplying secondary air into the exhaust manifold, Fig. 26. System operation is controlled by the ECM through a Three-Way Solenoid Valve (TWSV). According to the signal received from the ECM, the TWSV applies intake manifold vacuum to the second air valve, Fig. 26. This allows the reed valve, which responds to exhaust system pulsation, to draw filtered air into the exhaust manifold where it aids the combustion of HC and CO.