Are Loud Aftermarket Exhausts Legal on a 4×4?

You’ve probably seen (and heard) plenty of people out there with noisy 4×4 exhaust systems on their vehicles. Some people think that systems like this mean they’ll be noticed around town, that a loud car equals power. (Spoiler alert: it doesn’t.) Some people just might not know that letting their vehicles get out of regulation is illegal. The EPA has strict regulations around vehicle noise, though, as well as fines and sanctions for drivers who don’t follow the law.

What Makes an Exhaust System Loud?

According to the EPA, excessive noise from an exhaust system can be caused by:

• Replacement of original parts with a sports system, creating a ‘roaring’ noise
• Altered or removed baffles (muffler)
• A defective engine or exhaust system that allows gas to escape from places besides the exhaust outlet
• Modified noise control equipment that creates louder noise than what was intended by the original manufacturer

It is also illegal to use temporary noise reduction packages on your exhaust system. These include baffles that aren’t properly welded or riveted, adjustable valves, or steel wool placed into the exhaust system.

You do have options to alter your exhaust system, though. The Australian EPA allows for replacement exhaust parts or a whole system similar to that fitted when the vehicle was manufactured. If the system came with un-welded or un-fitted baffles, these are allowed.

How to Prevent Noisy Exhaust Systems

If you are purchasing a used vehicle, listen to the exhaust system. Does it sound overly loud or louder than other vehicles of the same make and model? Ask questions to confirm that it hasn’t been altered. If it has, you’ll need to purchase new parts to get it back to legal, factory standards.

Get your exhaust system and mufflers maintained regularly. If the pieces require replacement, choose high-quality parts that are going to last and keep your vehicle quiet on the road for the safety and experience of yourself and other drivers. If you are getting your vehicle serviced, ask questions to make sure that the equipment used follows EPA standards.

Legal Standards for Exhaust Systems

This gets a little tricky depending on when your vehicle was made. The Australian Design Rule (ADR) 83/00 passed in 2005. Any car that falls into the standards from before ADE 83/00 has different regulations than those that came afterwards.

If your 4×4 was built before January 1983, its max noise level is 96 decibels. Newer cars built before the 2005 ADR was passed have a max level of 90 decibels.

Vehicles that have compliance plates from before 1 September 2011 have a noise limit of what is stated in the EPA Schedule 1 or the ADR 83/00 signature level plus five extra decibels, whichever is higher. Those in compliance after this date have a decibel level limit of the ADR plus five decibels.

Getting Your Vehicle Inspected

The EPA takes reports about “noisy vehicles” very seriously. If your vehicle is reported, you might need to bring it into an inspection station for clearance that your exhaust system (as well as noise control and pollution equipment) is within legal requirements. If your vehicle has been reported by someone else, you’ll receive a vehicle inspection notice or VIN. It will tell you where to take your vehicle to get it inspected.

If your 4×4 exhaust is found to be out of regulation, you might have to pay a fine. Your vehicle registration could also be suspended. The fines associated with loud exhaust systems could also be issued immediately if you are pulled over by an EPA officer. It’s not just a one-noise-fits-all fine, either. The officer has the power to decide how loud your 4×4 is, then issue the amount of fine accordingly.

It would be smart to get your vehicle up to legal standards before bringing it into the shop for testing, too. You’ll be up against the clock though; your VIN will have a compliance due date and if you don’t get it completed in the required time frame, your fee could go up. If you need to bring it in more than once, it’s best to bring it to the same inspection station each time to avoid problems or delays.

Defective Vehicle Notices

Receiving a defective vehicle notice, or DVN, is also a possibility. You might receive a DVN if your vehicle has not met the time requirements for the necessary repairs or if you didn’t bring it into the mechanic shop for assessment at all.

When you receive a DVN from the EPA, it will instruct you to bring your vehicle into legal noise limits by fixing any defective equipment, or by refitting or repairing any necessary air pollution devices to lower the noise levels.

You have the option to do these repairs yourself or to bring your vehicle into a shop to have the 4×4 exhaust altered. However, even if you do it yourself, you must bring it to an EPA-approved shop to have it inspected and brought back into compliance. This must be done by the date on the DVN.

If you no longer own your vehicle (if it’s been sold, stolen, or if it was in an irreparable accident before the DVN due date), contact the EPA at infor@epa.nsw.gov.au or by phone at 02 9995 5700. If you’ve lost your DVN or you know that one was on the way and you didn’t receive it, contact the EPA for a replacement paper that you can take to an approved shop.

Staying within the Limits

It’s your responsibility as a 4×4 owner to ensure that your vehicle is running properly and within legal limits. Ignoring the notices and requirements of the EPA can result in higher fines and/or a suspension of your vehicle registration privileges.

If you need help maintaining your vehicle, reach out to a local auto shop that specializes in 4×4 exhaust systems. They’ll be able to help you determine what you need and how you can get back out on the road safely, legally, and respectfully.