Patent ID: 7991539
Filing Date: 2011-08-02
Classification: F01N,F02B,F02D,F02M,Y02T

Abstract:
1. An engine controller comprising an oxygen concentration sensor, which is located in an exhaust passage and detects oxygen concentration of exhaust gas, and learning means, which executes a learning process, the learning process including: a determining process in which when an integrated exhaust flow rate from when a fuel cut-off operation is started becomes greater than a predetermined amount, the learning means determines that ambient air in a vicinity of the oxygen concentration sensor in the exhaust passage has become atmospheric state equal to the oxygen concentration of atmospheric air as a fuel cut-off operation is executed; and a storing process in which a detection value of the oxygen concentration sensor at the time when the ambient air in the vicinity of the oxygen concentration sensor is determined to be equal to the atmospheric state is stored as a learned value, wherein the learning means corrects a detection value of the oxygen concentration sensor based on the learned value, wherein the learning means continues the learning process until a predetermined time period set based on an exhaust gas transport delay elapses from when the fuel cut-off operation is terminated.