| 摘要 |
A vehicle mounted engine control apparatus serves to prevent air fuel ratio control from becoming an excessively fuel rich state by sequentially actuating heaters for early activation of a pair of exhaust gas sensors arranged in an upstream and a downstream position of a catalyzer. Electric power is first supplied to a heater for an upstream exhaust gas sensor, and the supply of electric power to a heater for a downstream exhaust gas sensor is started without waiting for activation of the upstream exhaust gas sensor, if a heater current declines to a predetermined value or less. When the upstream exhaust gas sensor is inactive, an output signal of an upstream air fuel ratio control unit inputted to a fuel injection control unit is restricted to a predetermined fuel rich command, and when the downstream exhaust gas sensor is inactive, an output signal of an downstream air fuel ratio control unit inputted to the upstream air fuel ratio control unit is restricted to a predetermined fuel rich command. |
