METHOD AND APPARATUS FOR INSPECTING MECHANISM IN WHICH INSIDE OF EXHAUST PIPE OF INTERNAL COMBUSTION ENGINE IS SUPPLIED WITH SECONDARY AIR

摘要

PURPOSE: To minimize the quantity of secondary air introduced to exhaust gas in the monitoring process of a secondary air delivering system. CONSTITUTION: A secondary air pump 12 is switched on and builds up a pressure on a blocking valve. The valve closing member of the blocking valve 13 is acted upon by a predetermined closing force of an elastic element. If the secondary air quantity pumped by the secondary air pump 12 reaches a certain minimum air quantity, the blocking valve 13 is opened and a lambda sensor 10 disposed in an exhaust tube 5 detects a change in the lambda value in the exhaust tube that exceeds a predetermined threshold value.