Does Muffler Delete Void Warranty?

By September 10, 2020July 19th, 2021Common Questions

So you heard that muffler delete can greatly improve the sound of your car. But your car is kinda new and still covered under warranty. Will muffler delete void that warranty?

Well, No. With the Magnuson-Moss Warranty act, a muffler delete will not void the warranty of your car. For dealers to void your warranty, they must prove that the problem is directly caused by your modification. For example, if you perform a muffler delete and soon after your headlight stops working, then the warranty for the light still applies. But if you perform a poor muffler delete that causes your exhaust to break from rusting, then the warranty for your exhaust pipe won’t apply.

I think this is fair right? 🙂 Now let’s go to more details about the warranty act and other things you should know about before performing a muffler delete.

Recap: What’s a Muffler Delete?

If you are not familiar with the details of muffler delete, then this is the section for you. Otherwise move on to the next section about Magnuson-Moss Warranty Act.

You see, to produce power that moves car wheels, car engines create combustions in the combustion chamber. 

These combustions are controlled explosions that generate power and also produce loud noises in the form of sound waves – that travel through the exhaust pipe and out into the environment.

Without any silencing mechanisms, the noise produced can get extremely loud – even deafening  at times. Nobody likes loud car noises right? Except for the few car enthusiasts like us of course 🙂 

As car manufacturers, it’s natural that you want to sell as many cars as possible. Which means you need to appeal to the biggest market – people who don’t like noisy cars! To achieve this, car manufacturers equip mufflers in their cars and silence the engine noise significantly. 

Muffler delete means removing the muffler from your car exhaust system. This is done by cutting off the muffler and replacing it with additional exhaust piping instead.

It’s fairly easy to do – the hardest part is cutting off the muffler from the exhaust. If you can’t do this yourself, I am pretty sure any car workshop can help you.

Image of straight pipe exhaust
Exhaust system without a muffler.

Magnuson-Moss Warranty Act

Okay back to the warranty topic. I mentioned earlier muffler delete will not void your warranty because of the Magnuson-Moss Warranty Act. So what the hell is it really? Let’s covert it in simple words.

The “Magnuson-Moss” act protects you from being denied your warranty just because you have installed an aftermarket part or performed any modification. This act applies to any item costing more $20 or more and is a federal law in the United States – which means it applies to all states. Also, this act applies not just to cars and trucks but also ATVs, UTVs, boats, and motorcycles.  

To void your warranty, the dealer must prove that the problem you are experiencing is caused by the modification or aftermarket part.

For example, if you perform a muffler delete and then your transmission suddenly malfunction, the dealer cannot void the warranty on the transmission- unless they can prove the muffler delete is a direct cause somehow. 

So does this mean I am encouraging you to install any aftermarket part and perform any modifications to your car? No! Even with the “Magnuson-Moss” act you can still lose your warranty. I am pretty sure dealers have had tons of experience in dealing with the “Magnuson-Moss” act. They will be able to give you a pretty hard time and somehow create a link between your modification to the problem. 

You still have to proceed with your own risk and do plenty of research before committing to any aftermarket part or modification. Here’s what I really suggest if you want to perform modifications or install aftermarket part:

  • Only purchase aftermarket parts from reputable brand 
  • Research and understand what it is you are done and what the impact could be

Is Muffler Delete Legal?

Different states in the United States have different regulations – what’s legal in a state might not be legal in another. Complicated, I know. Out of all the states, California is the most strict – so I will base this topic around California.

Unfortunately, muffler delete is most likely illegal in California. Here’s the exact copy of the law in California “Every motor vehicle subject to registration shall at all times be equipped with an adequate muffler”.

Technically speaking you need to equip one muffler at all times in your car. However, most cars come with two such devices: muffler and resonator. Again, technically speaking, deleting a muffler from your car is still legal because you still have the resonator in your exhaust. Resonator is another sound suppressing device in your car that will silence the engine noise. 

These kinds of statements belong in the gray area. Personally, I wouldn’t take the risk but I just want to lay out all the information for you 🙂 . If you feel the gray area is good enough, then unfortunately for you, there’s another line in the California state law. “Vehicle weight rating of less than 6,000 pounds, other than motorcycles, [must have] a sound level of 95 dbA or less”. 

95 dbA or less. It’s hard for a car with muffler delete to achieve engine sound that’s 95 dbA or less – especially during a cold start. Even if you can, the engine sound after a muffler delete will still be loud and raise eyebrows of traffic police. 

I can’t cover whether or not muffler delete is legal in all states. I suggest you do your own research on this one. To make your life easier, here’s a list of laws from different states regarding exhaust noise. 

Will Muffler Delete Pass Smog Inspection?

Muffler delete will not impact your smog inspection. Muffler is purely a sound suppressing device – so removing it will not change your emission at all. Finally some concrete good point huh? 

While you perform a muffler delete, it’s important to make sure that the catalytic converter (CAT) is not touched. CAT takes the major role in keeping your car emission in check. If the CAT is somehow broken, you will surely fail your smog inspection.

Should You Perform Muffler Delete?

Here comes my opinion. I don’t think you should perform a muffler delete. This really depends on you but I think muffler delete is not the best way to improve engine sound. Just like we discussed, muffler delete is in the gray area when it comes to being legal. If your car is new and it’s a daily, I don’t recommend you put the car at risk with the law. 

Also, your car will become ridiculously loud after a muffler delete. I know there are a lot of people who might enjoy the sound. There are also many people who say muffler delete will make your car sound loud but not too loud – I think this is wrong. The engine sound after a muffler delete is very loud and can even be deafening from within the car. 

Another thing is that muffler delete requires you to cut the exhaust pipe so the muffler can be removed. This makes your exhaust pipe at risk of rusting – which can turn expensive real quick when the exhaust pipe splits apart. 

If you have a new car that’s still under warranty and you want an improved engine sound, I recommend you take a look at the list below. They are legal, will not void warranty and provide sound improvement that’s more aggressive but not necessarily too loud 🙂

Alternatives To Muffler Delete 

Resonator Exhaust Tip

Resonator exhaust tip is a small device that you clip onto your exhaust tail pipe for sound improvement. It’s cheap (about $30), legal, makes your car exhaust look sexy and is extremely easy to install.

Surprisingly, it works quite well. You will definitely hear the sound change and your engine noise will sound more aggressive. But it won’t be as loud as you want it to be.

Here’s a YouTube video showing before and after resonator exhaust tip. You can get plenty of resonator exhaust tips from Amazon.

Resonator exhaust tips are made of hollow chambers that are designed to cause sound waves to vibrate in a certain way and make them louder. If you know how a muffler works, resonator exhaust tip is the exact opposite.

Image of resonator exhaust tip
Resonator exhaust tip

Drill Holes In Exhaust Pipe

Drilling holes is another easy and cheap way to make your car sound louder. The trick is to drill some holes on the exhaust pipe right before the muffler. This allows sound waves travelling in the exhaust pipe to exit before they get silenced in the muffler. Resulting in a louder engine and more aggressive engine sound.

illustration of a car exhaust system
Drill holes here – right before the muffler.

Just make sure you drill the holes at the correct location. Don’t drill holes before the catalytic converter. If you do, toxic exhaust gases can exit the car before they are treated by the catalytic converter. This is a surefire way to fail your smog inspection. 

All in all, if done right, drilling holes is a cheap and quick way to make your car sound louder. It will not void your warranty and will not cause you to fail any smog inspection.

Here’s a YouTube video showing you how to drill holes in the exhaust. All you need is a drill and ⅜ drill bit

Cold Air Intake

Cold air intake is personally my favorite aftermarket install. They are usually marketed to improve horsepower but the real gem of cold air intake is the sound they produce. Cold air intake aims to boost horsepower by allowing more air flow and sucking only cold air instead of warm air from the engine bay. 

When you accelerate on a car with cold air intake, you can hear the unique sound of air rushing into your engine. I think this sound is cool, aggressive and unique. Here’s a YouTube video showcasing the sound I am talking about. Jump to 3:59

Here’s an article I wrote about cold air intake and the impact on sound. [/cold-air-intake-louder/] If you are already familiar with a cold air intake, I recommend you to get the K&I cold air intake. I am a firm believer of only installing aftermarket parts from reputable brands. The guys at K&I have been producing aftermarket intake for the longest time – I am sure they know what they are doing 🙂 Here’s an article I wrote about why K&I and what to look for when choosing cold air intake.

K&N Cold Air Intake
K&I Cold Air Intake
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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