IC engines are one of the major sources of noise pollution. Mufflers are generally found with exhaust system. After the combustion the high intensity gas pressure through the muffler chamber and some of the gases reflected again passes through the combustion chamber it is called back pressure. It creates vacuum pressure in combustion chamber and decreases the engine performance. Reduction of weight, increasing the capability of noise absorption from the muffler with minimal back pressure can increase the performance of the engine. The objective of this study is to optimize noise level of engine and reduce back pressure. This project mainly targets on designing a muffler to reduce the noise and back pressure. Based on new muffler design parameters, a model is fabricated and tested.