What Is a Muffler (What Does It Do + Other Common FAQs)

An exhaust muffler for your vehicle or any internal combustion motor is most simply described as an acoustic obstruction that helps quiet the exhaust noise an engine makes while running.

Why is it important to know this? Well, mufflers are a necessary part of your vehicle, so if you’d like to learn more about what they are and what they do, keep reading!

What Is a Muffler?

A muffler is a part of your vehicle’s exhaust system designed to keep your combustion engine quiet. Mufflers use a variety of chambers, insulation, and reverse acoustic technology to help deaden the engine sound. Particular mufflers can also be used to change the sound of a vehicle to the owner’s liking and even help a vehicle gain Horsepower.

Non-automobile enthusiasts may not see the use in knowing much about mufflers until they’re faced with replacing one. So, if you have questions, read on to find out what you need to know!

What Is the Difference Between Exhaust and Muffler?

An exhaust system usually routes the exhaust of the engine out to the back of the vehicle.

Somewhere in between the exhaust will be a muffler, or sometimes referred to as a “silencer.”

The muffler has to do more with deadening the sound that the engine makes before it goes out the tailpipes and into the atmosphere.

Is a Muffler Necessary?

A muffler is necessary by law. By not having one while driving on public roads, you could score yourself a ticket for defective equipment and or a noise violation.

It’s true, not having a muffler could help you add extra horsepower to your engine, and it may be perfectly legal to race without one at the racetrack, but it’s not legal to drive that way on a public roadway.

Does Changing the Muffler Increase Horsepower?

Does Changing the Muffler Increase Horsepower?

Depending on your vehicle’s setup, in most cases, moving to a less restricted muffler will give you anywhere from a 5-15 horsepower gain.

What Makes a Car Loud?

A number of things can make a once silent car loud, but the most common reason for a car to sound louder than it should would be an exhaust leak.

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An exhaust leak can come from where the exhaust manifold connects to the engine, where the manifold connects to the exhaust, or anywhere that an exhaust leak could have sprung.

Two other places that could cause a car to be loud: the muffler or the catalytic converter.

Both parts can leak at the connections or get damaged to where they can’t do their job, and having a hole in one of these parts can make a lot of engine noise.

What Is the Average Cost to Replace a Muffler?

An average cost of a muffler should be around $50-$80 on the low side. However, the newer, bigger, and more expensive the vehicle, the higher the cost.

Don’t be surprised if your high-end vehicle has a replacement muffler that costs somewhere in between $200-$800 before the cost of having it replaced.

Does a Muffler Improve Gas Mileage?

To help quiet a vehicle down, a muffler is implicated.

That muffler, especially if it’s a factory muffler, uses technology that creates a restriction in the exhaust flow, and restriction is always a fuel economy killer.

So, if you were to go with a bigger, less restricted muffler than what you already have, you should no doubt be able to gain some better gas mileage.

Will No Muffler Hurt My Engine?

Will No Muffler Hurt My Engine?

If your vehicle is from the early 2000s or older, then not having a muffler on your vehicle probably won’t hurt. Rather, it might even add a little performance.

But if you have a brand new vehicle, you might be doing your vehicle a disservice by running it with no muffler.

Brand new vehicles are so finely tuned to every aspect of the vehicle, including the muffler, that removing it could cause a power decrease.

As well, on a newer vehicle, you might notice your vehicle runs a little off-beat without a muffler, or your check engine light might even come on.

These days vehicles are so sophisticated, that it’s not a good idea to mess with the chemistry.

How Long Does It Take to Fix a Muffler?

Depending on where you go and if you have an appointment, a well-established muffler shop should be able to replace a muffler in about 30-90 minutes.

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If you have a high-end vehicle with a special exhaust, you would definitely want to make an appointment with your muffler shop, because it might not have the correct muffler for your vehicle in the inventory.

Is It Hard to Change a Muffler?

The project of changing a muffler for most people would be a little bit out of reach when it comes to skillset and tools.

A project like this would be better suited for a professional to handle.

The problem, however, is that sometimes metal cutting tools have to be used, and a lot of the time the muffler is by the gas tank, which is always a concern for a novice.

There is also the fact that muffles can oftentimes be hard to get to without a hoist.

They can also be a pain to replace, and when replacing them yourself, it’s a big bummer when they fall off a couple of days later from not being installed correctly.

Plus, when a muffler is incorrectly installed, it could make the same amount of noise as the old muffler that you are trying to replace.

Why Is My Muffler So Loud?

Why Is My Muffler So Loud?  

Mufflers usually don’t just go from being quiet to extremely loud without some type of damage happening to them.

If you run over something, or debris gets kicked up at the muffler, such instances could cause it to become louder.

When a muffler suffers a hole because of damage, you will notice a difference in sound immediately.

If the muffler breaks loose from one of its seals, it could take a while for the system to exhibit a noticeable sound difference.

However, this could also be due to the muffler being worn out.

Like most car parts, the muffler has an expiration date.

So, while you won’t notice it right away, over time your muffler will lose its ability to muffle the engine noise as efficiently as it did when it was new.

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Can You Put Duct Tape on a Muffler?

You may have heard of this quick fix before, or may have even seen someone do it before, but Do not attempt this.

Duct tape is made of cotton mesh covered with polyethylene plastic, and both materials will melt under high heat.

Consequently enough, the exhaust system is one of the places a vehicle gets the hottest.

When you have a muffler, or any exhaust problem that needs to be fixed, your best bet is to use a coat hanger or something similar to tie it up until you can get to the muffler shop.

Can Mufflers Be Repaired?

Unfortunately, in most cases, a muffler can’t be repaired.

The good news is that if you have an exhaust problem, but your muffler is still good, most shops can simply replace the segment of your exhaust system that needs repair, saving you a lot of money.

Do Mufflers Have to Be Welded On?

Mufflers can be installed without the use of a welder.

However, some applications do require some welding or hacksawing of the previous setup that may have been welded on.

Therefore, make sure to address these issues before you start a project on your own.

There is nothing worse than getting into something that should be an easy fix, only to find out that you should have taken it to a professional with professional tools.

To know more, you can also read our posts on what is a muffler delete, how much is a muffler delete, and how hot does a muffler get.


A muffler is part of your exhaust system that acoustically helps quiet your engine exhaust noise. Some mufflers are very simple and inexpensive, while others can be elaborate, and not so cheap.

Regardless, all mufflers wear out just like most auto parts, and you will one day have to get one changed. Your best bet is to set an appointment with a reputable muffler shop, and have it done before it gets so loud it annoys you or even gets you a traffic citation.

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