| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To accurately correct characteristics of an air fuel ratio sensor based on output of an oxygen sensor, in regard to an air fuel ratio control device for an internal combustion engine equipped with the air fuel ratio sensor in the upstream side of a catalyst and the oxygen sensor in the downstream side. <P>SOLUTION: Lean control of an upstream air fuel ratio is performed such that the catalyst is in a full state (Step 100 to 102). When the full state is formed, the upstream air fuel ratio is controlled such that output of the air fuel ratio sensor corresponds to a theoretical air fuel ratio corresponding value stoich (Step 104 to 106). When output O2 of the oxygen sensor 18 becomes lean output, it is determined that lean deviation occurs in stoich and the value is made richer (Step 112). When the output O2 becomes rich output, it is determined that rich deviation occurs in stoich and the value is made leaner (Step 120). When determination completion time passes while the output O2 remains stoichiometric output, the processing is completed without change (Step 116). <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
