in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine

Full Title

Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems > Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories > having two or more EGR passages; EGR systems specially adapted for engines having two or more cylinders > in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine