A method and a device for operating a combustion engine allow a plausibility check of two pressure sensors in a mass-flow line of the combustion engine in any operating range of the combustion engine. At least one component effecting a pressure drop is provided in the mass-flow line, and a first pressure is measured upstream from the at least one component with the aid of a first pressure sensor, and a second pressure is measured downstream from the at least one component with the aid of a second pressure sensor. The first pressure sensor and the second pressure sensor are checked for plausibility as a function of at least one modeled variable characterizing at least one pressure drop in the mass-flow line between the first pressure sensor and the second pressure sensor.