Method of controlling engine using heated exhaust gas sensor

摘要

There is provided a method of controlling an internal combustion engine system. The method comprises supplying a first amount of electric energy to heat to an upstream sensor located in an exhaust gas passage from the internal combustion engine and upstream of an exhaust gas after-treatment device and adjusting an air-fuel mixture supplied to the internal combustion engine based on an output of the upstream sensor during a first engine operating condition, and supplying a second amount of electric energy, which is smaller than the first amount, to heat the upstream sensor and adjusting the air-fuel mixture based on an output of a downstream sensor located in the exhaust gas passage and downstream of the exhaust gas after-treatment device during a second engine operating condition. By adjusting the air fuel ratio based on an output of the downstream sensor in the second engine operating condition, the air-fuel mixture can be adjusted under less influence from the condensed water, because the downstream sensor is located downstream of the exhaust gas after-treatment device. Therefore, during the second engine operating condition, the air fuel ratio can be more precisely adjusted.