Patent ID: 7788904

Claim:
An exhaust system for an internal combustion engine on a vehicle, having an exhaust catalytic converter and having a probe assembly in the area of the exhaust catalytic converter as a component of a lambda control device by means of which the internal combustion engine may be switched alternately between a lean-fuel operating range, in which the internal combustion engine is operated with a lean mixture having excess air and thus excess oxygen and a rich-fuel operating range, in which the internal combustion engine is operated with an air deficiency and thus oxygen deficiency, as a function of the probe signals detected by means of the probe assembly, wherein the probe assembly is in the form of a single lambda probe delivering a constant probe signal, such lambda probe being mounted downstream from the exhaust catalytic converter and by means of which, in conjunction with the lambda control device, the increase in the amount of oxygen in the exhaust gas flow is determined over the entire period of the lean-fuel operating phase and the decrease in the amount of oxygen in the exhaust gas flow is determined over the entire period of the rich-fuel operating phase, in relation to a specified oxygen amount reference value, an oxygen-dependent threshold switching value being specified which, when reached, causes switching of the lambda control device to the respective other area of operation.