There are 46 states in the nation that have muffler laws that have some element dealing with “excessive or unusual noise.” In these states, vehicle owners are required to keep the factory-installed muffler in the vehicle.
The only four states that do not have any such laws in place are Michigan, Oregon, Pennsylvania and Vermont.
Here is the law exactly as written in Tennessee:
55-9-202. Mufflers — Muffler cutouts prohibited — Penalty.
(a) No person shall drive a motor vehicle on any road, street or highway unless the motor vehicle is equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and annoying smoke.
(b) It is unlawful to use a “muffler cutout” on any motor vehicle upon any road, street or highway.
(c) A violation of this section is a Class C misdemeanor.
So, simply put, the answer is no—you cannot remove your muffler to increase your vehicle’s horsepower. We hear this question a lot at our muffler shop in Madison, TN, but it is against the law, and a misdemeanor, meaning you could face some fines and other potential penalties for doing so.
What exactly does a muffler do?
Since you’re required by law to keep this part in your vehicle, it’s probably a good idea to have at least a cursory understanding of what exactly it does.
The main function of a muffler is to minimize the amount of noise created by your vehicle. The muffler gets mounted in line with your vehicle’s exhaust pipe. Exhaust is the root cause of most of the noise that comes from your vehicle, as when your engine burns fuel, exhaust valves open up, releasing gas that is highly pressured (and thus quite noisy when released).
The muffler cools down the gas, which helps reduce the noise. The muffler also has a series of perforated tubes or baffled chambers. As the sound waves travel through the chambers, they create opposing sound waves that cancel out the original sound waves.
Depending on the design of the muffler, engineers might be able to create different sounds or weaker sounds. Much like you can create a musical instrument in a way that plays a higher or lower range of sounds and notes, you can do the same thing with the sound waves that come through your vehicle.
There are some people who like the sound of a vehicle with a muffler removed, and prefer to have a loud car rather than a quiet car. Some car engineers have been able to develop workarounds for owners who want some noise without having to remove the muffler, which would put them in violation of state law.
You might notice your muffler starting to make some unusual sounds. This could be a sign that it is breaking down or reaching the end of its useful life. If you’ve noticed this, it’s a good idea to contact a muffler shop in Madison, TN to make an appointment for muffler service. Visit Madison Muffler & Auto Repair or call to learn more.