The One-Stop Guide to Muffler Change: Everything You Must Know

By January 7, 2023January 10th, 2023Muffler

The muffler is a part of the exhaust system that deals with dampening the sound of the exhaust gas movement. As time has gone by, the function of the muffler has moved from just reducing the sound to tuning the sound of the exhaust. 

People now manipulate the muffler to make their vehicles sound more exotic. They can do this by changing the muffler into high-performing ones. 

Personally, I have changed the muffler of my Honda Civic to a  dual muffler. I notice a significant change in the sound of my vehicle. It sounds louder and more exotic. However, I did not notice any significant change in the performance of my engine—no added horsepower. 

I have compiled a helpful guide about all you need to know about mufflers and how it functions. This article should contain everything you need to know before you decide to change your muffler. I hope it helps you!

Note: Throughout this article, I will link to other more detailed articles on each topic. Visit all of them to really understand muffler upgrades before you commit.

Summary table:

Muffler Change The Impact
Sound change Can be louder or quieter depending on muffler
Warranty Not entirely void
Insurance Premium increased & needs to declare
Emission Test Pass
Fuel Consumption Normal
Horsepower None/Mild increase
Engine Damage No
Tuning required No
Cost $100-$300
Installation Cost $100
Installation Time 1-3hrs

What Is a Muffler & How Does It Work?

Muffler has the primary function of dampening the sound made by the exhaust gases coming from the engine. A Muffler is part of the vehicle’s exhaust system and can be found beneath the vehicle at its side. 

The exhaust can be very loud due to the sound wave created by combustion. These sound waves then travel through the exhaust system and get silenced by the muffler.

When the sound gets to the muffler, it is first slowed down. By slowing down the gases, it is easier for the muffler to carry out the silencing procedure. Then the sound wave will enter a series of compartments where the muffler will use these gases to cancel themselves or use other material to absorb the sound waves, depending on the type of muffler you will be getting. 

There are different sections in a muffler, and they are divided into three. 

1. Inlet

The inlet is the muffler part where the exhaust system’s gases and sound waves get into the muffler. 

2. Perforated tubes or chambers

Depending on your muffler, it could be absorptive tubes, perforated tubes, or chambers where the sound waves are silenced. 

3. Outlet 

The outlet is where the gases are then released back into the exhaust pipes, where they will flow out from the vehicle exhaust pipes. 

Why Should You Change Your Muffler?

People have numerous reasons why they change their mufflers. Some change them to get a more silent or louder sound. People change their muffler because the old one is damaged. 

Depending on the reason, changing the muffler comes with many benefits. You can achieve better airflow, sound, and fuel economy. 

Below are reasons why you should change your muffler. 

1. Better sound 

Exhaust Vs Muffler In Detail Horsepower, Sound & Cost

One of the reasons you can change your muffler is to achieve the desired sound you want for your vehicle. 

The muffler plays a vital role in the sound, and people use it to their advantage. By just changing your muffler, you can either make your exhaust more silent or louder. 

People buy performance mufflers to achieve a louder exhaust for their vehicles. Also, the size of the muffler plays a considerable role in your exhaust sound. Smaller exhaust is louder, and the smaller it gets, the louder the sound is. On the other hand, bigger exhausts are much more silent. The bigger the muffler, the more silent it is. 

2. Better gas flow 

Image of gas coming out of exhaust pipe

You can also achieve better gas flow by changing the muffler into a less restrictive one. The muffler can serve as a form of restriction to gas flow. When gases get into the muffler, they are slowed down, which is a restriction and can increase the level of back pressure. 

By changing the muffler, you can get one that will give you exhaust with a better gas flow. Not all mufflers are restrictive, and some have a free flow, like the straight-through muffler. Mufflers like this will eliminate many compartments in the muffler and provide a straighter path for gases to flow. 

3. Achieve better fuel consumption 

Getting a nonrestrictive muffler will help improve the airflow and thus, improve your vehicle’s fuel consumption. 

When your exhaust gas flows more freely, back pressure drops. The thing about backpressure is that excess of it affects the engine’s work and can also influence the O2 sensor reading, which could make the engine consume more fuel. 

When you change your vehicle’s muffler to a less restrictive one, your engine will receive a more accurate air-fuel ratio. It means that the engine will consume the right amount of fuel and not excess. 

Full details here: Does Changing Muffler Affect Fuel Consumption? (Tested)

4. Replace the damaged muffler 

When you have a damaged muffler, it could be disturbing and affect the driving experience. Like other parts of the exhaust system, when there is damage or leak, the sound and performance of the vehicle are affected.

It has many symptoms like engine misfires, disturbing sounds, poor fuel economy, etc. 

When you change the muffler, you automatically fix all the damages that the old one has. You also get rid of the symptoms that the damaged muffler showed. 

5. Improve engine performance 

By changing your muffler, you can improve the performance of your engine. You can get rid of back pressure that could cause the engine to reduce performance. 

Your engine will also be able to breathe well, and it will take in air through the intake and be able to release the byproducts of combustion freely without any form of restriction. 

These are the primary reasons you could get a new muffler, and it would help if you note that there are different kinds of mufflers. Each type of muffler comes with its features. When you decide to change the muffler, you need to consider the types of muffler that will suit your needs.

Bad Muffler Symptoms: How Could You Tell? 

When you have a bad muffler, it comes with different symptoms. The first sign you will notice is a loud sound coming from the exhaust system. Then it would be accompanied by other symptoms like engine misfiring, increase in fuel consumption, rusting parts and more. When that happens, you need to get your muffler changed. 

Below are signs telling you that your muffler is terrible and needs to be replaced.

1. Loud exhaust noise

The first sign that you will notice when something is wrong with the muffler is a change in the exhaust sound. Remember, the muffler serves the purpose of reducing the noise of exhaust gases coming from the engine. When there is a leak in the muffler, it will be unable to perform this function as the gas continues to exhaust from the leaks releasing all the sounds through the leaking parts. 

Your exhaust sound is meant to be silent, except you are using a muffler that alters the sound. If you do not and there is a sudden change in the sound, it is most likely a leak.

2. Exhaust smell

The exhaust system is designed so that all the gases are directed out of the vehicle through the tailpipe. When you smell exhaust fumes while driving, there is a leak somewhere, which could be your muffler. 

When you start smelling exhaust fumes in your vehicle, it could be dangerous to you and the passengers. It would help if you had the problem checked and fixed immediately. 

3. Engine Overheating

Many people do not know this, but your exhaust system plays a significant role in how the engine functions. When the internal components of the muffler fail, it becomes more restrictive, causing exhaust gases to move in and out of the muffler much slower. 

Once your bad muffler can slow down the gases more than usual, more back pressure is created. When there is too much back pressure, it will affect the flow rate and cause the build-up of gases to become hotter. In turn, the engine will also become hotter, causing overheating. 

In addition, you must know that it is not only a failed cooling system that causes the engine to overheat; excessive backpressure caused by a failed muffler or exhaust system can cause it too. 

4. Exhaust rust

Another sign that your muffler could be bad is a rusted muffler. Holes in the muffler could cause foreign elements like rain, snow, and more to get into it. When this happens, the muffler will begin to rust from the inside, which is quite difficult to fix that kind of rust. 

Unlike The outer parts of the muffler that can easily be recoated by anti-rust, the interior of the muffler cannot be. You will have to open up the muffler to do this. Better still, you get a new muffler when this happens. 

5. Check engine light

Check engine light is a common sign when the muffler is failing. It shows that the exhaust system is beginning to fail, affecting the engine’s proper functioning. As we have said previously, a failed muffler could cause more exhaust system restrictions, causing the engine to underperform. It could cause a check engine light to be triggered. 

Will Changing Mufflers Change The Sound Of a Car?

Changing your muffler can make your vehicle louder, silent, or maintain the typical sound. It all depends on the type of muffler that you get

A bigger muffler will result in a more silent sound, while a smaller muffler will have a louder sound. If you get a similar muffler as the OEM one on your vehicle, then expect the same sound. 

Changing your muffler will affect the sound of your vehicle. Some mufflers are designed to change the sound of your vehicle. For instance, a chambered muffler will give your vehicle a raspier sound and is not necessarily loud. 

A turbo-style muffler will give a deeper sound tone to the exhaust, which is also not that loud but sounds exotic. However, a straight-through muffler will be loud, and it will cause heads to turn and may attract the authorities. 

Mufflers like the absorptive muffler or mufflers with resonators will give your vehicle a much silent sound. These mufflers are designed with unique materials that can either absorb the sound exhaust gas sound waves or make them cancel themselves.

If you get a muffler similar to the original muffler on your vehicle, do not expect a change in the sound. Your vehicle’s sound will remain the same, except you will use other aftermarket exhaust modifications to tune the exhaust sound.

Full details here: Will Changing Muffler Change Car Sound? (Louder Or Quieter?)

Does Changing Muffler Void Warranty?

Changing your vehicle’s muffler will not void its warranty but will void the warranty cover on the muffler parts. Many people’s vehicle warranty was voided when they changed their muffler because it was not fixed properly.

The manufacturer can trace the vehicle’s fault to the changed muffler, which will void the warranty. 

A list of things can void your vehicle’s warranty, including using the wrong fluids, neglect from the user, and damages from aftermarket modifications. 

When it comes to aftermarket modifications like changing the muffler, it will not necessarily void the warranty on the vehicle after the instalment. However, when the modification causes damage to the engine, then the warranty will not cover the damages. 

You are advised to carefully consider the type of muffler to use with your vehicle and other modifications that will be used with it. 

Full details here: Warranty and Insurance Worries? A Guide to Muffler Upgrades

Does Changing Muffler Affect Insurance?

Any modification made to your vehicle (like a muffler) without disclosing it to your insurance company will void the insurance.

Modifications like a change in the muffler will change the amount of premium paid because the modification will change the value of the vehicle. 

Having the modification done without disclosing it to the insurance company will go against the insurance policy. 

Many insurance companies state in their policies that any modification done on the vehicle when taking the insurance cover must be declared. 

Also, a modification made after the insurance cover must be declared to the insurance company. The premium you pay to the insurance company is based on the vehicle’s value when you took the insurance coverage. 

Furthermore, going ahead to make such modifications without declaring it is intentional, not trying to pay the proper premium based on the vehicle’s value. If you do not tell your insurance company and they get to know after the damage has been done to the vehicle, it will void the insurance coverage, and you will not be indemnified. 

You can change your vehicle’s muffler any time you want to, but ensure that you inform your insurance company after the modification has been made.

Full details here: Warranty and Insurance Worries? A Guide to Muffler Upgrades

Does Changing Mufflers Affect Emission Tests?

The muffler does not have anything to do with a vehicle’s emission; changing it will not affect the emission of the vehicle. Your vehicle will pass the emission test if you have the modification done.

Many people have the misconception that mufflers influence emissions in specific ways. Many believe the muffler performs a similar duty to the catalytic converter in purifying exhaust gases. These beliefs are not accurate in any way. The muffler has one job, and it has to do with the sound produced by the exhaust system. 

When you change the muffler, relax when taking an emissions test; you will pass it as long as it is in good shape, not leaking, and there is no other problem with your exhaust system. 

Also, if the modification on your muffler affects either the catalytic converter or the O2 sensor, there will be a problem. The converter ensures that your vehicle does not emit dangerous gases; when these parts of the exhaust are damaged, your vehicle will emit dangerous gases. In this case, the vehicle will fail the emission test. 

However, it is rare for any modification on the muffler to affect the condition of the catalytic converter or O2 sensor. It is because of the distance between them from the muffler. However, a bad installation might affect the CAT, so you must be careful.

Full details here: Does Muffler Affect Emission Test? (Aftermarket & Deleting)

Does Changing Mufflers Increase Horsepower?

Changing the muffler on your vehicle will have little to no change in your horsepower. The muffler is a modification for sound and not to gain horsepower. 

Muffler change may not increase your vehicle’s horsepower; if it does, it will do little or nothing. Although some mufflers give horsepower gain, it is majorly reliant on the modification you have with the modification. 

Also, some mufflers, like the straight-through muffler, may give some horsepower. The straight-through muffler is designed to have little or no restriction; it can get rid of back pressure, allowing the engine to breathe more and increasing the vehicle’s performance. Even with this modification, the horsepower gain is between 10 to 15%. 

When installing a new muffler, it is best not to expect any horsepower gain, regardless of the muffler you are installing. 

Full details here: Do Mufflers Increase Horsepower: An Expert Weighs In

Can Mufflers Damage Engine?

Installing a new muffler will not damage your engine in any way. The modification will only affect the engine performance if you install a defaulted muffler; it could be too restrictive and cause the engine to overheat, misfire, and cause damage to the engine. 

The muffler can affect the engine in a way when it comes to gas flow and the way it can breathe freely, but changing the muffler will not damage the engine. Some mufflers have some restrictions, but these restrictions are not enough to create back pressure that will harm the engine. 

In simple terms, your muffler cannot damage your engine, but it can affect its performance if the muffler becomes bad. 

Full details here: Can A Muffler Delete Ruin Your Car?

Cost & Time To Put On Mufflers 

A muffler will cost $100 to $300 to get a new one (+ $100 for labour). Replacing or fixing any part of the exhaust system, including the muffler, will take between 1 to 3 hours for a professional and may take more time if you install it yourself. 

There are different types of mufflers, all of which provide different functions regarding sound and gas flow. The unique attribute of each muffler will add to how much it will cost. Some mufflers will cost more if they are high performance once. On the other hand, mufflers designed to be like the OEM muffler of your vehicle may cost less. 

Furthermore, installing a new muffler could be tasking, but it is something a professional can do within a few hours. However, if you will be doing it yourself, it could take a lot more time, primarily because you may need some tools as a professional. 

You may also have different knowledge than a professional to maneuver the tricky aspect and get the work done quickly. 

Full details here: Muffler Makeover: Costs & Installation For Every Vehicle Type

Does New Muffler Require Tuning?

Tuning your muffler after installing a new one is not necessary. Your muffler will work perfectly after installation and does not need any tuning to work right.

However, tuning the muffler could be a  good idea, as it has a few benefits and may allow you to add features you like to the vehicle. 

Before performing a muffler tuning, you should weigh the benefits and disadvantages. It will help you avoid wasting your time and money to find out you do not need the tuning.

Full details here: Do You Need To Tune After a New Muffler? (Myth Busting)


What’s The Difference Between Muffler & Exhaust?

The exhaust system is the part of the vehicle that handles the gas, a byproduct of engine combustion. It collects these gases and transfers them to different compartments like the catalytic converter and muffler. 

On the other hand, the muffler collects these gases and tries to silence or modify the sound created by its movement. It can achieve this by slowing down the gases and absorbing the sound waves. 

Can I Just Change The Muffler?

You can change your vehicle’s muffler anytime you want to, whatever type of muffler you want. Depending on your taste, you can get a much more silent or louder one. You can also get one that is less restricted and allows for more airflow. Some people decide to delete the muffler, which involves removing it entirely. 

Ifandi L.

Ifandi L.

Passionate about everything mechanical. Ifandi has been involved with motorcycles and cars since the old days - in his family's auto parts shop. Want to keep in touch? Scream "STRAIGHT PIPEEEEE" at the top of your lungs and Ifandi will show up.

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