Will Downpipe Void Your Warranty?

Installing downpipe will not void your car’s entire warranty. If you are living in the US, then you are protected by the Magnuson Moss Warranty act. For a dealer to void your warranty, they must prove how your aftermarket install is a direct cause to the issue. So for downpipe installation, you may lose warranty only for your exhaust, downpipe and turbo – not everything. 

If that’s too much to take in, it’s okay. Let’s go through everything in detail regarding downpipe, it’s warranties and any potential problems you may encounter from a downpipe.

The Magnuson Moss Act was enacted in 1975 to protect buyers from misleading supplier warranties. 

It defines various regulations like making warranties easily understood by consumers and cannot be misleading. But what I want to focus on is how this act can protect our car warranty when we perform modifications like a downpipe. 

In short, with the Magnuson Moss warranty act, to void your warranty, a dealer must prove that your aftermarket modification is a direct cause to the problem. 

So at the worst scenario, if your downpipe installation does cause a problem, you will lose the warranty for your turbo and exhaust pipes. Other components like electronics or spark plugs and batteries should still have their warranty intact. 

The Magnuson Moss act is a federal law in the US. So it should apply to you no matter the state you are driving on. 

Though  most of the time, having a good relationship with your dealer is key to having no warranty issues. If you really need to claim your warranty after downpipe installation, you should speak to your dealer with a respectful attitude and work things out. 

Going in there and pointing out about this act won’t help you solve anything! Plus, they probably know more about this act than you do. Just be informed and be respectful and you should be fine. 

Now that we have touched on the law, let’s discuss which components are affected by a downpipe installation and why. With this information, you should be aware of what component warranty is voided and what’s still intact. 

An aftermarket downpipe installation directly affects the turbo and exhaust pipe. This means after installing a downpipe, you will most probably void the warranty of your turbo and exhaust pipe. 

To understand why, we need to know what a downpipe does and how it’s installed. In short, an aftermarket downpipe is wider than stock and is less restrictive – which means they allow for a better exhaust flow, making your turbo spool faster and give you more power. 

If you want to know about how downpipe works, check out my other article over here. Are Downpipes Worth It? I cover how downpipes work and whether they are worth your money. 

A downpipe is directly connected to your turbo and exhaust pipe. Exhaust gases leave the combustion chamber and flow through your turbo to spool its turbine and power it. They then exit the turbo to the exhaust pipe through the downpipe. See the illustration below to understand this.

The fact that a downpipe is directly attached to the turbo and exhaust pipe is a big enough reason to void their warranty. And for turbo, a dealer has even more reasons to void it’s warranty because an aftermarket downpipe makes a turbo work much harder to generate that extra horsepower.

It’s very common for enthusiasts to tune their car after having a downpipe installed. Even I would recommend it – given the difference in horsepower gains. A catted downpipe without a tune could yield you 20 horsepower whereas a catted downpipe with a tune could give you 40 horsepower. 

You can read more about tuning and downpipe in my other article here. Running Downpipe Without Tuning (Should You?).

That being said, tuning will definitely void your warranty. Tuning a vehicle can impact the entire car components. Things like intake, turbo, fuel injection – literally everything in the car can be impacted by a tune. 

The Magnuson Warranty Act still applies here. To void any warranty, your dealer must prove how the tune is a direct impact. However, this is much easier to do than proving how the tune is NOT the cause. 

Also, you cannot just re-tune your vehicle to stock and then bring it in for warranty. Your ECU keeps track of your custom tune – allowing your dealer to identify your past tuning. 

Google  the “TD1 Flag” to know more. It’s basically a code that’s thrown by your ECU the moment you fiddle with the ECU.

1. Downpipe gives a great boost to horsepower. Catted downpipe with tuning can provide you with an additional 40 horsepower. Given the price, downpipe could be the cheapest aftermarket mod for horsepower boost. 
2. Downpipe makes your exhaust sound more aggressive. By being wider and less restrictive than stock, aftermarket downpipe allows sound waves to travel efficiently without bouncing and silencing each other out. I cover more on this here: Does Downpipe Make A Car Louder? 
3. Downpipe needs a tune for maximum horsepower gain. Without tuning, a catted downpipe can only give you about 20 horsepower gain. Not to mention, you will have the Check Engine Light on as well. It’s a standard to get a tune for downpipe installation. More on this topic here: Running Downpipe Without Tuning
4. Downpipe can give off an unpleasant smell. It’s very common for downpipes to give off the smell of unburnt fuel. For a catted downpipe this is not so significant – you wouldn’t smell it from inside the car. Catless downpipe is a different story though – you can smell it from inside the car when stopped at traffic. 
5. Downpipe is not street legal. Downpipes are not legal in any state in the US. It’s only meant to be used in track and off-roading. If you still insist, go for a catted downpipe – it will not be so apparent from eye inspection.
6. Downpipe costs about $850 to purchase, tune and install. The downpipe alone costs about $350, tuning comes in at $300 and installation at $200. You can definitely make this cheaper if you install it yourself and save the tuning for later when you also have aftermarket intake and exhaust. 
7. Go catted downpipe if you are installing on a daily driver. Due to its unpleasant smell and inspection, catted downpipe is a far better choice than catless downpipe for daily driving. Though catted downpipe is more expensive than catless, it will be worth it if you want to avoid problems.
8. Downpipe is worth the money if you are looking for horsepower. In case you are wondering, downpipe is definitely worth the money – especially if you are aiming for horsepower gain. I cover more about this topic here: Are Downpipes Worth It? 

Warranty is always a big topic when it comes to aftermarket mods. Unfortunately, there’s no other way around it – installing an aftermarket mod will always void some warranty. 

Just make sure you know the important things like the Magnuson Moss act and you should be well equipped to not get fooled! 

If you are a car enthusiast, I suggest you wait a little for the warranty to end. Maybe install other mods that won’t require a tune first. Things like mufflers and cold air intakes are great first mods – they are cheap, install easily, and won’t have a major impact on your warranty.