Diagnostic process for an exhaust gas catalytic converter of a heat engine and vehicle using this process

摘要

The present invention pertains to a process for diagnosing a catalytic converter processing the exhaust gases of a heat engine using a trap that stores and then reduces the nitrogen oxides (NOx) contained in these gases, these reductions being actuated as a function of the storage capacity of the trap. According to the present invention, such a process is characterized in that the oxygen ratio present in the exhaust gases downstream of the trap is measured by a sensor, and in that the storage capacity of the trap is determined by considering the time needed for the sensor to detect a threshold oxygen ratio in these gases during a reduction of the nitrogen oxides (NOx).