| 摘要 |
PROBLEM TO BE SOLVED: To delay progress of deterioration of an exhaust gas sensor while satisfying reduction of electrical load during automatic stop and demands for re-startability/improvement of fuel economy to some extent. SOLUTION: A catalyst 23 is provided in an exhaust pipe of an engine, and an exhaust gas sensor with a heater (oxygen sensor, air fuel ratio sensor or the like) are provided in an upstream side of the catalyst. Although fuel injection is stopped to stop the engine at timing t1 when predetermined automatic stop conditions are satisfied during engine operation, electricity carry to the heater of the exhaust gas sensor is continues even after automatic stop. Heater electricity carry time during automatic stop (automatic stop time) is measured by counting up automatic stop period heater electricity carry time counter Theat during automatic stop, electricity carry to the heater during automatic stop is stopped at timing t2 when heater electricity carry time during automatic stop exceeding heater electricity carry time established according to certain number of times of automatic stop which has correlation with progress of deterioration of the exhaust gas sensor. COPYRIGHT: (C)2008,JPO&INPIT
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