Detection of Catalyst Failure On-Vehicle Using the Dual Oxygen Sensor Method

On-vehicle proof-of-concept testing was conducted to evaluate the ability of the dual oxygen sensor catalyst evaluation method to identify serious losses in catalyst efficiency under actual vehicle operating conditions. This paper reports the results of a test program that used the dual oxygen sensor system coupled with a simulated on-board diagnostic algorithm to attempt detection of seriously deteriorated catalytic converters on a test vehicle operated over the Federal Test Procedure (FTP). This paper reports that, with some modifications, an algorithm was used to successfully distinguish between two properly converting catalysts and two poorly converting catalysts on the same test vehicle. For the covering abstract of the conference see IRRD 852385.