Patent ID: 7610750
Filing Date: 2009-11-03
Classification: F01N,Y02T

Abstract:
1. Method for monitoring an exhaust aftertreatment system comprising an injecting device operable to inject reductant into an exhaust gas feedstream upstream of a selective catalyst reduction device, comprising: determining a stoichiometric reductant/NOx ratio; controlling a rate of dosing from the injecting device to a non-stoichiometric reductant/NOx dosing rate; monitoring signal inputs from a sensing device that monitors the exhaust gas feedstream subsequent to passing though at least a portion of the selective catalytic reduction device; and, detecting a fault in the exhaust aftertreatment system based upon the monitored signal inputs solely from the sensing device subsequent to controlling the rate of dosing from the injecting device to the non-stoichiometric reductant/NOx dosing rate.