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.
Muffler (Secondary Exhaust System)
The muffler in your vehicle serves one main purpose; to quiet the natural sound
made by internal combustion engines. Mufflers come in all sizes and applications,
from the stock quiet one, to the throatier sound of a performance muffler. There
are basically two types of mufflers; noise canceling and material packed. In the
noise canceling (usually performance) barriers are welded into the muffler to reflect
the sound back into itself to cancel it out. In a material style there is a packing,
usually around a perforated tube that dampens the sound.
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.
Catalytic Converter - Used to convert unused fuel into
completely spent fuel
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.
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.
A performance exhaust system can be anything from a simple "cat-back" system
to give you a little better sound to a full tuned set of headers to replace the
restrictive exhaust manifolds. Always consult state and federal emissions laws before
modifying your vehicles exhaust system.
There have been numerous advances in the technology for performance exhaust systems.
While standard exhaust systems are designed as cost efficient as possible, a performance
system is usually made from a higher grade of material with a more performance-oriented
design. The exact type of performance exhaust often varies depending upon the vehicle
and application. Adding performance exhaust systems is easily handled with just
a few tools and will boost performance immediately.
Inspect your exhaust system on occasion to ensure that there are no cracks, holes
or rust. Only inspect the exhaust system after the engine has cooled down to avoid
burns. When exhaust replacement is required a performance exhaust system might be
a good consideration. After a new exhaust system has been installed it is normal
for funny smells to be produced. This condition will stop once the exhaust system
has been heated and cooled a few times. The reason for the smell is a new system
is manufactured using oils and paint and until the impurities are burned off it
will create an odor.
If further technical assistance is needed, our certified car repair technicians
are ready to answer your car questions.
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
