SECONDARY AIR SUPPLY SYSTEM FOR INTERNAL COMBUSTION ENGINE

摘要

Admission of secondary air is effected to remove a portion of exhaust gases staying in components of a secondary air supply system, particularly, a one-way valve with a pair of lead valves. The scavenging with the secondary air is carried out when the fuel supply to the engine is suspended under a predetermined deceleration condition. When the predetermined deceleration condition is satisfied, a secondary air shut off valve is opened even when a coolant temperature of the engine is so high that the secondary air is not required by a catalyst in the exhaust system.