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In order to match catalyst OBDII conditions the common procedure is oven aging with air, which is not suitable for complete converter systems due to mantle corrosion. The goal was, therefore, to find an alternative procedure to ensure a defined catalyst aging that would match 1,75 times the emission standard and is also good for SULEV. The new procedure currently being developed allows the aging of metal and ceramic catalysts as well as complete catalyst systems. The paper will present the aging process, emission data of fresh and aged catalysts and the feedback to the test car OBDII system.

Nearly all real Diesel engine operation is leading to low exhaust temperatures. Standard catalyst technique remains therefore for significant time below light off. To improve the conversion behavior two approaches were made: placement of tailor fitted catalysts as close as possible to the engine exhaust port before turbocharger and usage of close coupled catalysts with the so-called hybrid design. Both measures are providing visible progress in reducing Diesel engine emissions. Tests were made with modern Diesel engines both for passenger cars and heavy duty vehicles.

1 An experimental study has been carried out on a production vehicle by means of roller-bench emission tests in order to optimize alternative aftertreatment systems. To this aim different comparisons between the production exhaust system and new strategies are discussed in the present paper with aid of both modal emission data and bag tailpipe figures. The present work shows the application of a alternative solution that complies with future emission legislation with regard both to HC, CO, NOx and PM without any major engine power output or fuel consumption penalty.

Nearly all real diesel engines operations are leading to low exhaust temperatures. Standard catalyst technique remains therefore for significant time below light-off. To improve the conversion behavior two approaches were made: placement of tailor-fitted catalysts as close as possible to the engine exhaust port before turbocharger and usage of close coupled catalysts with the so-called hybrid design. Both measures are providing visible progress in reducing diesel engine emissions. Tests were made with modern diesel engines both for passenger cars and heavy-duty vehicles.