The error message “Check exhaust system” was shown to me. Since the car was running perfectly and there was no power drop, the error was only deleted. 3 days later the error message came up again. The error memory was read out and the exhaust gas return valve was renewed. Again 3 days later, the error message appeared again. Then the AGR was “fished”. 3 days later the error message now lights up again. has anyone had the same experience here? VG A. Balz