METHOD FOR MANAGING A FUEL SUPPLY OF A SPARK IGNITION INTERNAL COMBUSTION ENGINE AND A SUPPLY SYSTEM IMPLEMENTING SAID METHOD

Method of managing a fuel supply of a spark ignition internal combustion engine (E), wherein a procedure is provided for controlling a respective combustion so as to alternately oscillate between a lean- burn condition and a rich-burn condition, the method comprising the following steps: * - a step for detecting a cut-off condition, wherein a fuel injection is inhibited, * - a second step for calculating a variation in the oxygen stored in said catalyst with respect to an optimal storage value; * - a third step for controlling said fuel supply of the internal combustion engine, at the end of said cut-off condition, so as to neutralize exclusively said excess oxygen with respect to said optimum storage value.