Abstract: The invention relates to a method for the cylinder-selective control of an air/fuel mixture to be burnt in a multi-cylinder internal combustion engine, in which the lambda values for different cylinders or groups of cylinders are separately sensed and controlled, and also relates to a multi-cylinder internal engine suitable for carrying out the method. In accordance with the invention, the lambda values of the individual cylinders or groups of cylinders are simultaneously controlled to different required values using an integrating I-control proportion with variable integrator slope and/or a differentiating D-control proportion.

Abstract: Thermal shock reactions of a heated lambda probe owing to the impact of liquid droplets on the heated ceramic probe body during cold starting, which phenomenon can lead to a fracture of the ceramic probe body, are avoided, and a better representativeness of the signals transmitted by the lambda probe is achieved, in that a gas deflector plate is arranged before the lambda probe in the exhaust gas flow, as seen in the direction of flow of the exhaust gases, in such a way that the lambda probe lies in its Lee.

Abstract: A process and equipment for removing toxic and malodorous gases from the fresh air for vehicle cabins by catalytic oxidation, the process being based on passing the fresh air over a heating-system heat exchanger, the heat-emitting surfaces of which form the support for an oxidation catalyst. The heat exchanger used is the heating-system heat exchanger which is present in virtually all motor vehicles. In contrast to known solutions for purifying the fresh air, for example by means of activated carbon, the process is maintenance-free and does not require any additional constructional volume.

Abstract: A method for testing and adjusting catalytic exhaust gas emission control systems of internal combustion engines, in which the fuel-air-ratio is regulated by means of a .lambda.-probe (control-probe) arranged in the exhaust gas stream upstream of the catalyst, whereby the exhaust gas stream is measured downstream of the catalyst by means of a further .lambda.-probe (test-probe). The voltage average value and amplitude magnitude of the signal produced by the test-probe are determined and serve for adjusting the operating point of the control system and for the recognition of the catalyst efficiency.