Patent ID: 6557341
Filing Date: 2003-05-06
Classification: F01N,Y02T

Abstract:
An exhaust system for an internal combustion engine having two groups of cylinders, a separate exhaust line for each group of cylinders, each exhaust line including an upstream catalytic converter, a downstream catalytic converter, and a control valve, a first transverse connection extending between said exhaust lines upstream of said upstream catalytic converters and a second transverse connection extending between said exhaust lines between said upstream and said downstream catalytic converters, said control valves being so arranged and controllable that, during an initial warm-up period, the exhaust gas from both groups of cylinders is conducted through an upstream catalytic converter in only one of the exhaust lines and through a downstream catalytic converter in the other exhaust line for rapidly heating one of the catalytic converters in each of said exhaust lines and, after the upstream catalytic converter of the one and the downstream catalytic converter of the other exhaust line have reached critical operating temperature, the exhaust gas from each group of cylinders is conducted separately through its associated exhaust line and its upstream and downstream catalytic converters.