Patent ID: 6918245
Filing Date: 2005-07-19
Classification: F01N,Y02T

Abstract:
1. A secondary air feeding apparatus, comprising: a secondary air feeding passage that supplies secondary air to a region upstream of an exhaust gas purification unit of an internal combustion engine; an air pump disposed in the secondary air feeding passage; an opening-closing portion which is disposed downstream of the air pump and which switches an opening-closing state of the secondary air feeding passage; a pressure sensor disposed between the air pump and the opening-closing portion, wherein the pressure sensor outputs pressure values; and an abnormality detection portion that detects abnormalities in components on the basis of an average of the pressure values, wherein the average is calculated based on the output pressure values detected by the pressure sensor within a predetermined period, before and after the switching of the opening-closing state of the opening-closing portion as detected by the pressure sensor during the operation of the air pump and on the basis of a difference between the average pressure values.