| 摘要 |
PROBLEM TO BE SOLVED: To provide an abnormality diagnosing device of an air/fuel ratio sensor capable of diagnosing the abnormality precisely in a short period of time. SOLUTION: The abnormality diagnosis routine is executed during the fuel recovery operation after the fuel cut operation. The quantity ΔA/F of change of the air/fuel ratio during a prescribed change quantity calculation period ΔT is calculated one by one (S15) based on the output of the air/fuel ratio sensor (S11), and the maximum value ΔA/Fmax of a plurality of these quantities of change and a previously set criterion value ΔA/Fsaf are compared (S19). When the maximum value is smaller than the criterion value, it is determined that the air/fuel ratio sensor is abnormal (S24). |
