Exhaust gas cleaner system for an automotive internal combustion engine includes an air introduction pipe 8 for introducing secondary air, heated initially by a heater 23, to the catalytic converter unit 7 mounted on the exhaust pipe 3. The ignition timings of the engine is retarded at least during the time when the secondary air is heated by the heater 23. Preferably, the number of ignition timings are counted by a counter modulo 5, for example, in the case of a four-cylinder engine, and the ignition timings are retarded when the counter content is 3 or 4, such that the ignition timings of the cylinders are retarded intermittently. Alternatively, the retardation of the ignition timings may be terminated before the introduction of the heated secondary air is terminated.Where two first and second catalytic converter units 7a and 7b are provided, secondary air distributed by a change-over valve 10a is heated separately by heaters 23b and 23c.To reduce the burden imposed on the engine, the generation of power by the AC generator 28 may be suspended when either the flow control valve 10b or the heater 23 is operated.