Apparatus for controlling air-fuel ratio of internal combustion engine

摘要: To control the air-fuel ratio of an internal combustion engine without variations and thus suppress deterioration exhaust gas, a canister for adsorbing evaporated fuel is connected to tank. A release passage connects intake tube engine. purge duty cycle flow rate valve installed in this passage. An ECU provides feedback according oxygen concentration controls idle speed via ISC valve, by vacuum switching valve. As carried out, gas released from purged. The makes decision, non-purging mode, as whether amount purged reaches limit that critical value tolerated at each instant time. If result will be reached, execution inhibited. At time, established range rates might hinder operation