Failure detection apparatus for an internal combustion engine

摘要

A failure detection apparatus for an internal combustion engine includes failure detecting means (S 22 -S 30 ) for detecting abnormality of fresh air quantity detecting means (air flow sensor) based on the result of comparison between a fresh air quantity detected by the fresh air quantity detecting means (air flow sensor) and a fresh air quantity reference value set by fresh air quantity reference value setting means (S 20 ), and exhaust flow rate adjusting means. The fresh air quantity reference value setting means sets the reference value (S 16 ) in accordance with not only the operating state (engine speed N_e, fuel injection quantity Q_f, etc.) of the engine but also a target adjustment amount (target throttle valve opening) set for the exhaust flow rate adjusting means by target adjustment setting means (S 12 , S 14 ).