Exhaust catalyst monitoring arrangement
In a motor vehicle having an engine with an exhaust catalyst and an oxygen sensor upstream of the catalyst and an oxygen sensor downstream of the catalyst, a method for detecting whether the catalyst has aged. Over a test block period of time, the method periodically obtains upstream data points from an oxygen sensor located upstream of the catalyst and from and oxygen sensor located downstream of the catalyst. Absolute differences are calculated between consecutive pairs of the upstream data points and the downstream data points. A ratio between the sums of absolute differences is then calculated, and the ratio is used to determine whether the catalyst has aged.
DaimlerChrysler Corporation
F F F Y F F F F F
F02D F02D F02D Y02T F02D F01N F02D F01N F02D
additional inventional inventional additional additional additional inventional inventional additional
Craig Richard K Dave Bill Tom Douglas M Mark J Chris J Jason E Wei Danny K
Summers Moote Carlson Leisenring Stephens Stander Poublon Booms Wielenga Wang Schuelke