Patent ID: 8037672
Filing Date: 2011-10-18
Classification: F01N,Y02T

Abstract:
1. A method of sensing and signalling a non-operational status of a catalyst in a catalytic converter in an exhaust conduit of a combustion engine, the engine having a fuel charge supply apparatus providing a fuel charge to combustion chambers of the engine with a predetermined air/fuel ratio in response to a pre-catalyst oxygen sensor in the exhaust conduit, the method comprising the steps: providing a post-catalyst temperature sensor in the exhaust conduit; reading the post-catalyst temperature sensor to provide an initial sampled exhaust gas temperature; providing a quantity of unburned fuel through at least one of the combustion chambers to the catalytic converter during an idle period of engine operation while temporarily suspending a response of the fuel charge apparatus to the pre-catalyst oxygen sensor; monitoring the post-catalyst temperature sensor at a predetermined propagation delay time after providing the quantity of unburned fuel to provide an additional sampled exhaust gas temperature; comparing a temperature difference between the additional sampled exhaust gas temperature and the initial sampled exhaust gas temperature with a predetermined reference value; and signalling a non-operational status of the catalyst if the temperature difference does not exceed the predetermined reference value.