Patent ID: 8776500

Claim:
An exhaust treatment system for a hybrid vehicle, the exhaust treatment system comprising: an electrically-heated catalyst (EHC) configured to receive exhaust gas from an engine of the hybrid vehicle and including an electric heater and a hydrocarbon (HC) adsorber; a three-way catalyst (TWC) located downstream from the EHC, wherein the TWC is not electrically heated; an air/fuel ratio control module that selectively commands a rich air/fuel ratio for a first period upon starting an engine of the hybrid vehicle when a temperature of the EHC is less than a first temperature, wherein the first period is sufficient to fill the HC adsorber; an air pump control module that selectively activates an air pump supplying air into the exhaust system upstream from the EHC based on whether the engine is on and at least one of whether the HC adsorber is full and whether the EHC is saturated with oxygen; and an electric heater control module that selectively activates the electric heater of the EHC based on whether the engine is on and the temperature of the EHC, wherein the air pump control module selectively activates the air pump when the engine is off, the HC adsorber is full and the EHC is not saturated with oxygen.