The exhaust system of a semi-truck is responsible for routing used gases away from the engine and into the atmosphere. It starts at the exhaust manifold, where gases exit the engine, and ends at the tailpipe. In between, there are a number of different parts that work to clean and route the exhaust. These include the catalytic converter, diesel particulate filter, muffler, and resonator. They all serve their own specific function, but they work together to create a safe environment inside the cab while also helping the driver maintain optimal performance on the road.

Mufflers come in two types: A straight pipe and an acoustic one. Straight pipes reduce noise levels by trapping sound waves inside themselves before releasing them outside as wasted energy. Acoustic mufflers also reduce noise levels but use tuned tubes to absorb some of those sound waves before releasing them as wasted energy outside of the vehicle’s frame. Catalytic converters are designed to convert carbon monoxide into harmless molecules like water vapor and carbon dioxide with help from small amounts of platinum or rhodium inside them. Diesel particulate filter (DPF) design to remove diesel particulate or shoot from the exhaust.