About Exhaust System

Automotive exhaust system consists of a hot-end exhaust pipe, a catalytic converter, a muffler, and a cold-end tailpipe.

 

 

1,Hot-end exhaust pipe

 

It is directly connected to the automobile engine, where the high-temperature exhaust gases pass through first. It is equipped with an oxygen sensor, which senses the oxygen molecule content in the exhaust and feeds this information back to the Electronic Control Unit (ECU), thereby determining the mixture ratio entering the engine.

 

2,Catalytic converter

 

It is integrated into the hot-end exhaust pipe to purify the exhaust gases. It uses catalyst to clean the automobile's exhaust by converting harmful substances in the exhaust into harmless ones. Catalytic converters come in various types, such as two-bed, oxidation, and three-way types, among which the three-way catalytic converter is the most commonly used. As long as the exhaust passes through the three-way catalytic converter, it can efficiently convert the three main harmful substances in the exhaust into harmless substances.

 

3,Muffler

 

It is connected to the hot-end exhaust pipe and contains baffles, chambers, holes, and tubes. It utilizes the phenomenon of acoustic wave reflection interfering with and canceling each other out, gradually weakening the sound energy to reduce noise decibels. Although the muffler can reduce noise, it also reduces some engine power, which is why some racing cars do not install mufflers.

 

 

4,Cold-end tailpipe

 

The cold-end tailpipe is connected to the muffler and serves as the final section of the exhaust system, discharging exhaust gases from the vehicle. There are two types of cold-end tailpipes: dual exhaust and single exhaust. Generally, V-type engines (engines with cylinders arranged in a V-shape) or other large-displacement L-type engines use dual exhaust, while small-displacement L-type engines use single exhaust.