Patent ID: 8650858
Filing Date: 2014-02-18
Classification: F01N,F02D,Y02T

Abstract:
1. An exhaust emission control apparatus for an internal combustion engine, comprising: an exhaust gas purification catalyst that is arranged in an exhaust gas passage of the internal combustion engine and that purifies an exhaust gas; an air/fuel ratio sensor that is arranged on an upstream side of the exhaust gas purification catalyst and that detects an air/fuel ratio of an exhaust gas that is discharged from the internal combustion engine; air/fuel ratio feedback control means that performs feedback control of the air/fuel ratio of the internal combustion engine based on an output of the air/fuel ratio sensor; and sensor output correcting means that corrects a shift in the output of the air/fuel ratio sensor that is caused by a component included in the exhaust gas; wherein the sensor output correcting means is configured so as to correct a shift in the output of the air/fuel ratio sensor using a lean shift amount of the output of the air/fuel ratio sensor in accordance with a quantity and/or a proportion of an aldehyde included in the exhaust gas.