Catalyst deterioration diagnostic device and diagnostic method
AssigneeToyota Jidosha Kabushiki Kaisha
InventorShunsuke Fushiki
Life of this patent
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Abstract
A device for diagnosing deterioration of a catalyst by a decrease in oxygen storage capacity, in which the oxygen storage capacity by which the catalyst deterioration is diagnosed to be present when exhaust gas recirculation is not implemented is higher than the oxygen storage capacity by which the catalyst deterioration is diagnosed to be present when the exhaust gas recirculation is implemented.
Claims8
A device for diagnosing deterioration of a catalyst on the basis of a decrease in oxygen storage capacity, said device comprising:
- a determination section that determines whether the catalyst has deteriorated by comparing a value of the oxygen storage capacity with a determination value, the determination value, used when exhaust gas recirculation is not implemented, being higher than the determination value used when the exhaust gas recirculation is implemented.
A method of diagnosing deterioration of a catalyst on the basis of a decrease in oxygen storage capacity, said method comprising:
- determining whether the catalyst has deteriorated by comparing a value of the oxygen storage capacity with a determination value, the determination value, used when exhaust gas recirculation is not implemented, being higher than the determination value used when the exhaust gas recirculation is implemented.
A device for diagnosing deterioration of a catalyst, comprising
- a determination section that determines that the catalyst has deteriorated when oxygen storage capacity is lower than a first value while exhaust gas recirculation is implemented, and that determines that the catalyst has deteriorated when the oxygen storage capacity is lower than a second value larger than the first value while exhaust gas recirculation is not implemented.
Dependencies are inferred from the claim text.