Patent ID: 6205774
Filing Date: 2001-03-27
Classification: F01N,F02D,Y02T

Abstract:
A method for detecting flow-reducing changes in an exhaust-gas catalyst body of an exhaust-gas purification system during the operation of an associated internal combustion engine with at least one engine cylinder, said at least one engine cylinder having a plurality of operating conditions that produces exhaust gas that impinges upon the exhaust-gas catalyst body, said at least one engine cylinder includes an ion-current measuring probe associated therewith that produces an ion-current signal, said method comprising:identifying a minimum strength desired for said ion-current signal;monitoring said strength of said ion-current signal produced by said ion-current measuring probe associated with said at least one engine cylinder;comparing said strength of said ion-current signal to said minimum strength of said ion-current signal; andproviding a warning indicating a flow-reducing change in said catalyst body when said strength of said ion-current falls below said minimum strength.