METHOD FOR MONITORING SUPPLY OF AIR TO EXHAUST GAS OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To avoid problems of the strong adhesion of oil caused by a lambda control circuit and/or the deteriorated operability of an internal combustion engine by increasing the amount of air taken by the internal combustion engine when the air is supplied to the exhaust gas. SOLUTION: When an answer of a step 3.1 of a main program is YES, a step advances to a step 3.2 of increasing the air flow of an internal combustion engine and then advances to a step 3.3 of activating a secondary air pump. Since the oxygen concentration in the exhaust gas is increased in a secondary air system with not malfunction, a lambda control applies oil a little. It is checked in a step 3.4 whether oil is applied or not and, when the answer is YES, the secondary air system is judged to be normal and the secondary air pump is stopped and the step returns to the main program. When the answer of the step 3.4 is NO, it shows that excessive oxygen does not exist sufficiently in the exhaust system, which shows that the secondary air system has a malfunction. Therefore, a malfunction alarm is output in a step 3.8.