Apparatus for diminishing nitrogen oxides

In an apparatus for diminishing the amount of nitrogen oxides in the exhaust gases of an engine of the type having fuel injected into its cylinders, the improvement which comprises an injector associated with the intake system of the engine for injecting fuel into said intake system;

• a sensor for nitrogen oxides installed in the exhaust system of the engine downstream of a catalytic converter for detecting the concentration of nitrogen oxides in the exhaust gases leaving said converter;
• and means for controlling the amount of fuel injection by said injector in accordance with the load of the engine and the output of said sensor.

In an apparatus for diminishing the amount of nitrogen oxides in the exhaust gases of an engine, the improvement which comprises an injector associated with the exhaust system of the engine for injecting fuel into said exhaust system upstream of a catalytic converter;

• a sensor for nitrogen oxides installed in said exhaust system downstream of said converter for detecting the concentration of nitrogen oxides in the exhaust gases leaving said converter;
• and means for controlling the amount of fuel injection by said injector in accordance with the load of the engine and the output of said sensor.

In an apparatus for diminishing the amount of nitrogen oxides in exhaust gases of a fuel injected engine having a load applied thereto, said engine having a cylinder, an intake system and an exhaust system, the improvement which comprises an injector associated with one of the intake system and the exhaust system of the engine for injecting fuel into one of said intake and exhaust systems;

• means for determining the amount of nitrogen oxides in the exhaust gases;
• and means for controlling the amount of fuel injected by said injector in accordance with the load of the engine and the amount of nitrogen oxides in the exhaust gases.