The invention relates to a method that is intended for operating an internal combustion engine of a motor vehicle and that flushes the temporarily unused injection valves with fuel for the purpose of preventing and/or removing deposits. In order to make possible in a simple way a complete conversion of the undesired exhaust gas constituents in a catalytic converter of an exhaust gas aftertreatment system of the internal combustion engine when the internal combustion engine is running, the invention proposes flushing the temporarily unused injection valves with fuel during an overrun mode of the internal combustion engine.