METHOD FOR OPERATING AN EXHAUST-GAS CLEANING DEVICE FOR A MOTOR VEHICLE AND CORRESPONDING EXHAUST-GAS CLEANING DEVICE

A method for operating an exhaust gas cleaning device for a motor vehicle, the exhaust gas cleaning device has a vehicle catalytic converter, a first lambda probe arranged upstream of the vehicle catalytic converter, and a second lambda probe arranged downstream of the vehicle catalytic converter. A signal gradient is determined chronologically between a first signal jump of a measured value of the first lambda probe and a second signal jump of the measured value in a second direction opposite to the first direction, and a signal delay of a measured value of the second lambda probe is determined after the second signal jump.