EXHAUST EMISSION CONTROL DEVICE FOR ENGINE

摘要

PROBLEM TO BE SOLVED: To improve an NOx purifying rate by a catalyst. SOLUTION: When an exhaust gas flow rate Vex is below a given value Vexo (a step S6) and a catalyst temperature Tcal exceeds a given value Tcato (a step S7), by varying a fuel injection form (a step S8), an HC amount in exhaust gas is increased or an exhaust gas temperature is lowered.