What is the function of the mid-section of a car's exhaust system?

[WyattRose]

The mid-section exhaust pipe serves to reduce gas flow velocity, exhaust noise, and exhaust temperature. Below are the relevant details: 1. A car's exhaust system consists of the exhaust pipe, catalytic converter, muffler, tailpipe, etc. 2. The exhaust pipe is the pathway for exhaust gases. Its chassis layout, pipe length, diameter size, and muffler size all affect the flow of exhaust gases, preventing interference between exhaust streams from adjacent cylinders. In fuel-injected engines, the oxygen sensor is installed on the exhaust manifold, detecting the oxygen content in the exhaust and feeding this information back to the Engine Control Unit (ECU), which then determines the air-fuel mixture ratio entering the engine. 3. The exhaust manifold connects to the catalytic converter, whose function is to purify the car's exhaust gases using catalysts, converting harmful substances in the exhaust into harmless ones.