Method and system for diagnosing deterioration of NOx catalyst
A system and method for diagnosing deterioration of a nitrogen oxide (NOx) catalyst for an internal combustion engine. An output signal indicative of concentration of nitrogen oxides (NOx) in exhaust gas passing through the NOx catalyst is generated from a NOx sensor. Rates of change in the detected...
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Main Authors | , , |
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Format | Patent |
Language | English French German |
Published |
16.12.2009
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Subjects | |
Online Access | Get full text |
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Summary: | A system and method for diagnosing deterioration of a nitrogen oxide (NOx) catalyst for an internal combustion engine. An output signal indicative of concentration of nitrogen oxides (NOx) in exhaust gas passing through the NOx catalyst is generated from a NOx sensor. Rates of change in the detected NOx concentration are calculated a plurality of times over a predetermined period of time after an air/fuel ratio becomes less than a stoichiometric air/fuel ratio. A representative value derived from the calculated rates of change in the detected NOx concentration is compared with a predetermined reference value for determining that the NOx catalyst is deteriorated. |
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Bibliography: | Application Number: EP19990102539 |