Patent ID: 8516796
Filing Date: 2013-08-27
Classification: F01N,Y02T

Abstract:
1. A diagnostic system for an exhaust system of an engine comprising: a first electronic circuit configured to, in response to a request for a fuel inhibiting event, operate said engine in a first rich condition for a first period until a catalytic converter of said exhaust system is in a predetermined first rich state, subsequently cut off fuel to said engine for a second period contiguous with said first period, subsequently operate said engine in a second rich condition for a third period contiguous with said second period, and subsequently cut off fuel to said engine for a fourth period contiguous with said third period; a second electronic circuit configured to determine a catalyst efficiency of said catalytic converter based on an output of an oxygen sensor located downstream of said catalytic converter during said second period, to selectively adjust a diagnostic status of said catalytic converter based on a comparison of said catalyst efficiency and a predetermined catalyst efficiency, to determine a first responsiveness of said oxygen sensor based on said output during said second period, to determine a second responsiveness of said oxygen sensor based on said output during said third period, and to selectively adjust a diagnostic status of said oxygen sensor based on said first responsiveness and said second responsiveness; and an information display that communicates the diagnostic status of said catalytic converter to a user, wherein one or more operating parameters of said engine are selectively adjusted based on said diagnostic status of said catalytic converter.