Correction system of an output signal of an oxygen sensor

The system has an engine operating conditions monitoring unit (16) including a detection unit (24) that detects stopping of fuel injection in cylinders of a diesel engine (8), to activate operation of an effective signal acquiring unit (18) and a drift coefficient determining unit (20). A correction unit (22) corrects an output signal of an oxygen sensor (4) according to the drift coefficient determined by the unit (20). The drift coefficient is determined between an effective signal delivered by the sensor and a theoretical output signal of the sensor.