Exhaust emission control system and method

Power plants – Internal combustion engine with treatment or handling of... – Having sensor or indicator of malfunction – unsafeness – or...

Reexamination Certificate

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C060S274000, C060S285000, C060S286000, C060S297000

Reexamination Certificate

active

06941744

ABSTRACT:
An exhaust emission control system for an internal combustion engine is provided which includes a NOx storage/reduction catalyst disposed in an exhaust passage of the engine, and a NOx sensor positioned in the exhaust passage downstream of the catalyst. A controller of the system performs a rich-spike operation to temporarily operate the engine at a rich air/fuel ratio each time a NOx storage state of the catalyst satisfies a predetermined rich-spike condition during a lean-burn operation. When the degree of degradation of the catalyst is determined by comparing the output of the NOx sensor with a predetermined evaluation value, the rich-spike condition is changed so that the amount of NOx stored in the catalyst at the time of a start of the rich-spike operation during a degradation determination period is made larger than that reached during a period other than the determination period.

REFERENCES:
patent: 5735119 (1998-04-01), Asanuma et al.
patent: 6167695 (2001-01-01), Itou et al.
patent: 6195987 (2001-03-01), Miyashita
patent: 6357224 (2002-03-01), Kawamoto et al.
patent: 6460329 (2002-10-01), Shimotani et al.
patent: 6484493 (2002-11-01), Takanohashi
patent: 6487851 (2002-12-01), Okada et al.
patent: 6568179 (2003-05-01), Deeba
patent: A 7-208151 (1995-08-01), None
patent: A 2000-130212 (2000-05-01), None

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