Patent ID: 7257943
Filing Date: 2007-08-21
Classification: B01D,F01N,F02D,Y02A,Y02T

Abstract:
1. A system for controlling exhaust emission oxides of nitrogen (NOx) during restarts of an internal combustion engine (ICE), the system comprising: a first sensor for determining a first level of exhaust gas oxygen at a location upstream of a catalytic converter; a second sensor for determining a second level of exhaust gas oxygen at a location mid-bed of the catalytic; and a controller for performing at least one process to reduce NOx emissions when a difference between the first level of exhaust gas oxygen and the second level of exhaust gas oxygen exceeds a predetermined amount, the at least one process comprising at least one of delaying an engine restart for a predetermined time or limiting the number of restarts to a predetermined number during a selected interval of time.