Method of heating catalyst through system cooperation and vehicle

A method of heating a catalyst through system cooperation, the method comprising:

• transmitting, by an engine management system (EMS), a bit when preheating of an oxygen sensor is required and when an engine torque is required in a catalyst heating (CH) environmental condition;
• when bit does not equal 1, determining an engine start permission timing, by a hybrid control unit (HCU), using the bit and transmitting an engine load operation (lock-up CH) mode command and changing a transmitting command to an engine no-load operation (idle CH) mode command;
• and
• operating, by the EMS, the engine with the engine load operation mode command or the engine no-load operation mode command;
• wherein the bit is classified into a lock-up CH bit according to the need of the preheating of the oxygen sensor, and an engine start enable bit according to the need of the engine torque,
• wherein the determination of the lock-up CH bit applies a state in which the oxygen sensor does not reach an activation temperature as a preheating available condition, and the lock-up CH bit is generated when the preheating of the oxygen sensor is completed;
• wherein the determination of the engine start enable bit applies a vehicle speed condition requiring an engine torque together with a motor torque in a preheating unavailable condition, and the engine start enable bit is generated when reaching a vehicle speed according to the vehicle condition;
• wherein in the performing of the engine load operation (lock-up CH) mode, when bit=1, an engine load operation mode condition is determined by confirming a shift stage and demand power to determine a part load of the engine as a part load (PL) CH demand torque, and a part load state together with the PL CH demand torque is transmitted to the EMS;
• wherein the CH environmental condition is determined as a quick drive away state or a cold quick acceleration state of a vehicle;
• and
• wherein the quick drive away state and the cold quick acceleration state are applied in a normal ambient condition of 0 to 30° C. or −7 to 35° C. and a vehicle state in which the parallel HEV/PHEV type vehicle may not travel with only the drive motor.