We have all pulled up next to one of those cars with a souped-up engine and a small or nonexistent muffler. This car wants to be seen, heard, and loved. Well, it is definitely seen and heard. . .the loving part is subjective.

If that’s the kind of sound you are going for, great! If you’d enjoy a quieter ride, then paying attention to your muffler and exhaust system is key. If you’re in the market for a used car, you should also pay attention to this part at the used or rebuilt title car dealers. While it isn’t as exciting as the paint job, taking a good look at the muffler and exhaust system when you are doing a test drive can not only help you spy any future troubles, but it can give you a glimpse into how well the car has been maintained.

But, what exactly do the exhaust system and muffler do? Is it just noise reduction?

Let’s start there.

How to Diagnose Muffler Trouble (“Is it Supposed to Sounds like That?”)

(Leeloo Thefirst/Pexels)

What Mufflers Do and How They Work

Clearing the Air

The exhaust system is designed to get rid of the toxic gas created by fuel combustion, namely carbon monoxide. A car engine works sort of like the human body, in that it takes in oxygen and puts out carbon monoxide, but in much stronger doses. That carbon monoxide can be dangerous and the muffler is part of an exhaust system that pulls those toxic fumes away from the engine and the car’s occupants.

Control the Sound

Getting you where you want to go takes quite a bit of combustion and movement, so it isn’t surprising that an engine makes a lot of noise, especially when it is a powerful one or in acceleration. Mufflers contain a series of pipes and tubes that diffuse the air coming from the engine. This doesn’t just diffuse the sound, it is designed to create a level of sound that meets the sound waves from the engine noise and cancel it out. That’s why the length of the muffler matters. Its shape plays a part in the sound waves.

By now, we hope you’re convinced that the muffler is important. It is also pretty vulnerable. Its location exposes it to plenty of wear and tear. It has a few major enemies:


This one is a danger to those cars that drive in wintry climates. Salt is wonderful for thawing ice. But that capacity to erode ice doesn’t work so well when the salt sprays on your muffler. Salt will corrode and wear down a muffler, so if you drive on salted roads regularly, give that undercarriage a good rinsing from time to time.

Speed Bumps

Vehicles with a high clearance might not deal with this risk, but if you drive a car that is low to the ground, speed bumps should slow you down. A muffler sits at the bottom of the car and taking that speed bump too quickly could loosen or damage the muffler. When in doubt, slow it down.


Any damage from salt or speed bumps can cause more trouble down the road because it increases the risk of rust. Rust finds damaged metal and does its job, and its job is corrosion. Rust is good at its job, but employing it on your muffler is a bad idea. Rust is the oxidation process between iron and water, so if there is water, there can be rust. And if there is rust, there can be holes.

And what if there are holes? How will you know? Unless you roll under your car daily for an inspection, you probably won’t notice a muffler problem right away. Your car will let you know in its own way. Here are the signs of a possible hole or leak in the muffler:

You Need to Drive with Earplugs
Sometimes change is so gradual you might not notice it at first, but if others mention something or you notice the car is making quite a bit of noise, then the muffler is the first place to check for trouble. A hole in the muffler means the sound system of tubes and pipes can’t find the right balance and the car engine noise isn’t going to be muffled.

More Frequent Fill-Ups
Car engines need air to make everything work. The engine pulls in the air, and the exhaust system pushes it out. If something is off in the exhaust system or muffler, then that whole system will break down, causing the engine to pull in oxygen less efficiently. This inefficiency will show up at the gas tank, lowering your miles per gallon rate and raising your gas budget. If you keep track of your mpg (which we highly recommend) and notice it is getting worse, the exhaust system could be the culprit.

That sound isn’t just unsettling, it is also a sign that the airflow balance is off in your car. That bang is a sign that the push and pull system is off-kilter and, as a result, making some unwanted noise. It might be funny in the movies, but it is a sign of bigger troubles when it happens in real life.

The exhaust system and its champion, the muffler, are often unsung heroes of your car. They stay low, get the job done, and deal with all the toxic side effects in the workplace. But sometimes, issues arise. These issues, as well as the belching black smoke that a bad exhaust system can conjure up, aren’t just annoying quirks, they can be dangerous. A hole in your muffler or some other part in the exhaust system could redirect carbon monoxide back into the vehicle, which can cause serious health concerns. It can be gradual and indiscernible, but very risky. If you spot any of these troublesome symptoms, have it looked at right away.