Splitflow catalyst system

A method of reducing exhaust emissions comprising the steps of:

• providing at least one exhaust canister including an inlet separated from an outlet with catalytic components positioned between the inlet and outlet, the at least one exhaust canister receiving a flow of exhaust gas, the at least one exhaust canister including a pair of concentric passages formed therein including a central passage and an outer passage;
• providing a split flap valve positioned in the inlet;
• providing an actuator coupled to the split flap valve;
• providing a control unit operably connected to the actuator;
• determining an exhaust gas temperature;
• determining a cold start condition;
• selectively moving the split flap valve closing one of the concentric passages and locally heating a portion of the catalytic components.