The exhaust system in your car has three main functions. First it transfers
poisonous exhaust gases from the engine to the rear of the car. Secondly, it
quiets down the engine sound while running. Finally, it converts unspent fuel
into spent fuel with the help of a
catalytic converter. The
exhaust system consists of an exhaust manifold, exhaust
pipe, catalytic converter,
muffler and tail
pipe. There are endless configurations of exhaust systems from the
very loud free flow, low restriction system to the barely audible system
depending on application and driver preference.
Exhaust Manifold
An
exhaust manifold
is used to transfer exhaust gases from the exhaust port of the cylinder head to
the exhaust pipe. Most exhaust manifolds collect between 3 and 6 ports depending
on application. The exhaust manifold sometimes houses the fuel management system
oxygen sensor. The mounting port for the primary oxygen sensor is located in the
beginning section of the exhaust system, before the catalytic converter. The
secondary sensor is located downstream of the catalytic converter. These sensors
are used to monitor the density of exhaust gases and relay information to the
main PCM controller.
Primary Exhaust System
This is a typical primary exhaust system. The function of the primary system
is to transfer the exhaust from the exhaust manifold through the head pipe and
flex pipe to the catalytic converter. The catalytic converter has a heat shield
to protect the floorboard from the extreme heat it creates. An exhaust system is
held in place by rubber exhaust hangers to help dampen engine vibration and to
allow the system to flex without breaking. Most exhaust systems are made of
aluminized metal or stainless steel to prevent corrosion. Engines produce water
along with the exhaust gases as a natural byproduct of the combustion process.
This is why a small amount of water and steam is observed coming from the
exhaust pipe when the car is cold. As the engine heats up the water is vaporized
quickly so the moister is not visible.
Secondary Exhaust System
The secondary exhaust system is used to transfer the exhaust from the catalytic
converter through the muffler and out the rear of the vehicle through the tail pipe.
System Components
Exhaust Manifold: bolted to the cylinder head and is used to gather
exhaust gases from the many cylinder ports to one location where the head pipe
is connected.
Head Pipe: the tube that connects the exhaust manifold with a exhaust
flange and the other end to the catalytic converter
Exhaust Flange: the connector union between the exhaust manifold
and the head pipe
Exhaust Pipe: the pipe that is used to connect the various components
of the exhaust system
Muffler: used to reduce the audible sound frequency developed by the
engine.
Secondary Muffler: sometimes called a resonator the secondary muffler
furthers the sound deadening of the engine exhaust.
Exhaust system hanger: a metal strap connecting the exhaust system
to the bottom of the car. They are usual made with a rubber insulator.
Tail Pipe: the tube that is connected to the muffler that continues
to the back of the car.
How Exhaust is Created
Additionally, it is essential to have an exhaust system that moves the potentially
harmful emissions as far away from the passengers of the vehicle as possible. Many of
the fumes that exit the engine are quite harmful and can cause complications to
passengers including lightheadedness, blurred vision and even in extreme cases death.
Due to these safety concerns, having a properly working exhaust system should be
an absolute must have for everyone, regardless of emissions laws in your area.
Common Problems
Defects or corrosion in the exhaust system causes exhaust gases to be consumed
causing asphyxiation
After driving long distances the exhaust system can become very hot causing
ignition of dried timber or grass under vehicle
Only Inspect exhaust system when the engine is cold to avoid burns
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