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One way of increasing the efficiency of a gasoline engine is to operate it in lean-burn mode. However, a lean mixture in the combustion chamber reduces its ignitability, which leads to poor combustion stability and even misfires. This investigation presents a solution to this problem using an active pre-chamber for each cylinder, into which fuel can be injected separately and in which ignition takes place. This increases the ignition energy in the main combustion chamber, thus enabling stable combustion. Cylinder-specific feedback control of the fuel quantity injected into the pre-chambers was implemented on the basis of measured cylinder pressures so as to compensate for injector component deviations, achieve maximum efficiency, and prevent increased emissions. Since combustion delay and burn duration are dependent on the fuel mass injected into the pre-chamber, an additional feedback control for the center of combustion (MFB50) was integrated along with the fuel quantity controller.