| 摘要 |
During a rich spike control for an exhaust gas purification system for an internal combustion engine, a base air-fuel ratio AFb is decreased in a range where a combustion variation &Dgr;CC does not exceed a permissible limit &Dgr;CCL (S108). When the combustion variation &Dgr;CC exceeds the permissible limit &Dgr;CCL, the spike base air-fuel ratio AFbs is increased (S213). When the torque decrease amount &Dgr;TD is above the permissible value &Dgr;TDL, the spike base air-fuel ratio AFbs is decreased (S215). When the combustion variation &Dgr;CC is above the permissible limit &Dgr;CCL, and the torque decrease amount &Dgr;TD is above the permissible value &Dgr;TDL, the spike base air-fuel ratio AFbs is increased, and a fuel discharge time number EN is increased (S216). |
