TWO-STROKE ENGINE ASSEMBLY HAVING A CATALYTIC CONVERTER AND METHOD FOR CONTROLLING SAME

A two-stroke engine assembly has a two-stroke internal combustion engine (ICE) and an exhaust system fluidly connected to the ICE. The exhaust system has a tuned pipe and at least one catalytic converter. A bypass valve is provided to selectively bypass the at least one catalytic converter. A method for controlling a two-stroke engine assembly controls the ICE to bring the temperature of exhaust gases within an operating temperature range of the catalytic converter. Another method for controlling a two-stroke engine assembly uses a lambda sensor to control the air-fuel ratio in cylinders of the ICE.