Patent ID: 8087233

Claim:
A vehicle diesel engine exhaust gas purification system comprising: an exhaust gas purification device provided in an exhaust passage of a diesel engine; a secondary fuel injection device for performing secondary fuel injection in a cylinder of the engine after a primary fuel injection, to supply fuel to the exhaust gas purification device and thereby maintain purification performance of the exhaust gas purification device; a control unit configured to detect a degree of dilution of engine oil of the diesel engine; an indicator coupled to the control unit and that indicates to an occupant of the vehicle that the engine oil needs to be changed when the control unit detects that the degree of dilution of the engine oil is equal to or greater than an allowable degree; wherein the control unit also is configured to control the secondary fuel injection device to (i) prohibit execution of the secondary fuel injection when the indicator indicates that the engine oil needs to be changed, and (ii) override the prohibition of the execution of the secondary fuel injection until a prescribed period has elapsed after the indicator indicates that the engine oil needs to be changed.