Abstract: A method for the dynamic diagnosis of an exhaust gas analyzer probe situated in an exhaust-gas system having at least one exhaust-gas catalytic converter, of an internal combustion engine, a measuring signal (lambda-actual) of the exhaust gas analyzer probe being compared to a setpoint value (lambda-setpoint) as a function of the operating state of the internal combustion engine, and the system deviation being supplied to a controller, which regulates the operating parameters of the internal combustion engine correspondingly, the dynamic diagnosis of the exhaust gas analyzer probe being implemented with a closed control loop, and the deviation from the setpoint value (lambda-setpoint) of the measuring signal (lambda-actual) of a slowing exhaust gas analyzer probe being amplified by the intervention of the controller and the dynamic diagnosis is implemented on the basis of this amplified deviation.

Abstract: A method for the dynamic diagnosis of an exhaust gas analyzer probe situated in an exhaust-gas system having at least one exhaust-gas catalytic converter, of an internal combustion engine, a measuring signal (lambda-actual) of the exhaust gas analyzer probe being compared to a setpoint value (lambda-setpoint) as a function of the operating state of the internal combustion engine, and the system deviation being supplied to a controller, which regulates the operating parameters of the internal combustion engine correspondingly, the dynamic diagnosis of the exhaust gas analyzer probe being implemented with a closed control loop, and the deviation from the setpoint value (lambda-setpoint) of the measuring signal (lambda-actual) of a slowing exhaust gas analyzer probe being amplified by the intervention of the controller and the dynamic diagnosis is implemented on the basis of this amplified deviation.

Abstract: A method for operating an internal combustion engine and a device for implementing the method may allow a catalytic converter diagnosis with a high degree of accuracy. At least one catalytic converter is positioned in the exhaust-gas region of the internal combustion engine, and a lambda sensor, which is configured as broadband lambda sensor, is positioned downstream from the catalytic converter or downstream from a section of the catalytic converter. The catalytic converter diagnosis is based on the evaluation of a measure for the oxygen storage capacity of the catalytic converter/within the catalytic converter. An at least approximately empty/filled oxygen reservoir of the catalytic converter is assumed. A change in the lambda setpoint value of the internal combustion engine to an excess air factor lambda that is greater than 1/less than 1 follows. Subsequently, a first change of the lambda signal is detected initially.

Abstract: A method for regulating the fuel/air ratio of a combustion process which is operated alternatingly with excess air and air deficiency, and having at least one catalyst volume in the exhaust gas of the combustion process which stores oxygen when there is excess oxygen in the exhaust gas and gives it off when there is oxygen deficiency, in which method the oxygen charges into the catalyst volume taking place when there is excess air, and the oxygen discharges from the catalyst volume taking place when there is air deficiency determined, and in which the fuel/air ratio is regulated in a first control loop such that the sum of the oxygen charges and oxygen discharges determined in a predefined interval takes on a predetermined value, wherein the combustion process is operated using oxygen excess or oxygen deficiency, respectively, at least until these appear at an oxygen-sensitive Nernst probe downstream from the catalyst volume.