What Are Muffler Deletes?
A muffler delete is essentially the removal of the vehicle’s muffler, leaving the exhaust pipes open to the atmosphere at the rear of the vehicle. This type of modification, commonly referred to as a "straight pipe," allows for greater exhaust flow from the engine and is intended to improve vehicle performance. However, this type of modification can have a loud and sometimes obnoxious effect on the sound the engine makes when operating at higher RPMs. This is what leads many owners of performance vehicles to perform a muffler delete. The increased exhaust flow allows the engine to create an "aggressive" sound, which many cars enthusiasts find appealing, especially those who have modified their engines and exhaust systems for added performance. It is important to note that just as the muffler delete will likely enhance an engine’s performance amid high revs – it may also diminish the engine’s potential at low revs , along with impacting the efficiency of the vehicle’s emissions control system. This is largely due to the passive effect of the muffler. Many newer vehicles, including those manufactured by Ford, Chevy, and Dodge, are equipped with an active muffler which allows drivers to switch between a quiet mode and a performance mode. This feature gives drivers the best of both worlds. However, if an owner of a performance vehicle chooses to replace the active muffler with a straight pipe or some other type of aftermarket muffler, they will likely end up with a loss of sound control, which can be a disadvantage when you are driving in a residential area or want to avoid drawing attention to yourself and your vehicle.
California Muffler Deletes Laws
In California, the relevant state codes that regulate the use of muffler deletes are found within the California Vehicle Code. Section 27150 of the code states that every motor vehicle that is operated on a California highway must be equipped with a "muffler or other noise dissipating system." The basic purpose behind this law is to prevent excessive and unreasonable noise levels that can be detrimental to the public health and safety. Therefore, this law does not explicitly address the use of muffler deletes in and of itself.
The next relevant state code is Section 27007, which states, "no person shall use any sound amplification system from any motor vehicle on a highway or any public space adjacent thereto which is audible at a distance of 50 feet from the vehicle." A muffler delete, which is typically characterized by an open-exhaust system where no exhaust muffler is even present on the exhaust system, can therefore be considered a loud enough and completely audible "system" that constitutes a violation of the law.
This same law also states that no "person shall so operate or allow to be operated any motor vehicle so as to cause excessive, annoying or unnecessary noise." In order to determine if a particular vehicle is in violation of the section 27007, law enforcement officers can use their own subjective judgment to determine whether the level of noise from that system is, in fact, "excessive, annoying or unnecessary." In other words, if a law enforcement officer determines that the sound produced by a vehicle’s open exhaust system is likely to disturb the peace, such as it would in the case of a vehicle with a muffler delete, then the officer must issue a citation.
While owners of vehicles with muffler deletes may receive citations, they generally do not carry heavy fines or penalties. Violating vehicle code section 27007 is punishable as an infraction with a fine of $10 for a first offense, $25 for the second offense and $50 for a third or subsequent offense. Section 27150 is punishable by a fine of $250.
Muffler Deletes Impact on Safety and the Environment
Considerations of noise pollution can also be considered in relation to the legality of muffler deletes, as one of the hallmarks of these modifications is their propensity to produce far louder watch your language here as opposed to stock exhaust systems. In and of itself, this does not categorically mean that they are illegal, as noise ordinances vary in strictness by municipality. Muffler deletes, however, generally operate at much higher levels of decibels ever disturbing members of the public to the extent that local law enforcement will be made aware of their use, or will see such vehicles as being suspicious, thereby inviting scrutiny as to their legality. In these instances, drivers of cars with these types of modifications may be given a warning, citation, or even be subjected to the registration being flagged which can result in a driver being pulled over.
In addition to noise pollution, other emissions are an important consideration of whether muffler deletes are legal in California. Muffler deletes, as they relate to exhaust system modifications in general, are staged in the same manner: the muffler (between the catalytic converter and the tail pipe) is removed to increase noise and airflow in the exhaust system. In many instances, this will be done along with the addition of new catalytic converters, or even the removal of them altogether. This poses a problem as modern vehicles have onboard diagnostics to monitor the performance of emissions systems. Essentially, if the modified exhaust system is functioning normally, it is likely that no codes are being triggered and the vehicle is not flagged. If there is a problem with the emissions system, the check engine light will trigger, and the codes will be obtained and noted in the system. Now, the smog station has the option of sending the electronic record into the Bureau of Automotive Repair, and this would allow the vehicle to be randomly placed into testing.
The penalties faced for having a vehicle that violates emissions standards can be steep, ranging anywhere from hundreds to thousands of dollars in fines, as well as having the vehicle inspected for compliance. Failure to comply will result in the vehicle being flagged until compliance is shown, and can create issues when attempting to obtain a smog certification for registration purposes. These penalties are considered by many to be excessive, especially in relation to the very minor pollution created by muffler deletes and other exhaust modifications.
Legal Muffler Delete Options
Resonator deletes, commonly employed in tandem with exhaust modifications, are frequently confused with muffler deletes, which are altogether illegal. Resonator deletes, which are legal, offer similar benefits – enhanced vehicle sound and improved performance – without running afoul of California’s stringent regulations. To be clear, resonators are not mufflers, and are typically located further upstream in the exhaust system, between the catalytic converter and the muffler. They serve the critical purpose of attenuating specific, unwanted frequencies in the exhaust output. When deleted, a vehicle’s exhaust system will produce a uniquely different sound – one, as the name implies, that lacks the dampening impact of the resonator. This results in a more pronounced and aggressive tone.
If the twin goals of enhancing performance and sound are to be achieved, and the muffler delete is illegal , what are the options? As is readily apparent from the above comparison chart, a cat-back exhaust upgrade has the potential to deliver most, if not all, of the same benefits as a muffler delete, but within the bounds of the law. Defined broadly, "cat-back" refers to virtually any exhaust modification that extends from the catalytic converters or head pipes to the tips. Within this broad definition reside a number of exhaust options, including resonator deletes, axle back variations, and a host of cat-back systems, which may or may not replace the resonator and/or muffler.
The only pre-requisite for a cat-back system to be legal is that it not exceed the existing sound-level restrictions. Unlike muffler deletes, which are always "too loud," a cat-back system may be perfectly legal so long as it does not exceed 95 dB at an idle, per California Code of Regulations Title 13, Section 971.
Muffler Deletes: Consequences, Enforcement, and Realities
The enforcement of muffler deletes as it is done on the road is primarily left to local law enforcement. While regulations exist regarding noise pollution that extend to vehicles, the exact recourse against drivers for noise violations is left somewhat open to interpretation. Generally, however, muffler deletes will be documented and then fined at the discretion of the officer, whether that is primarily through the use of propriety noise testing equipment or by simply applying their own judgment based on what they have heard and witnessed.
As muffler deletes only tend to materialize on heavily modified and tricked out cars, specification of which exactly vary, it can be hard to estimate how much fines would actually total for a given driver or the frequency of the application of tickets, however anecdotal evidence aids in clarifying these topics. One reason these vehicles are so often modified is that vanquishing the muffler is an incredibly common and relatively low-cost series of modifications, easily accomplished by someone with the instructional videos to hand on a subject and a little mechanic know-how.
For example, one video guide recommended a directed method for performing the deletion, with a recommendation to "make sure you wear your gloves and goggles," and "keep a fire extinguisher handy. These things get hot." A muffler delete can be as easy as simply removing the muffler and replacing it with a straight pipe in order to achieve the same goal, or else purchasing a new one that promises a "fierce race car roar." Noise ordinances as applied to such after-market modifications leave it up to local codes and discretion.
While custom exhaust systems like muffler deletes alone are unlikely to be ticketed as they rarely are specified as taps on noise ordinances, if a driver is pulled over for another violation or some other traffic infraction, a muffler delete may compound these legal burdens.
Addressing a Muffler Delete
If you are a resident of California and currently have a muffler delete it’s important to know that you are in violation of the law and could face costly penalties. Because of this, you probably have already thought of ways to become compliant with California laws or you have already purchased a new exhaust system.
If you are looking to purchase a new exhaust you should look into having a muffler assembly installed. If you replace your old exhaust with an aftermarket exhaust assemble you will be complying with CA law so the problem of a muffler delete will go away. However , simply picking any exhaust system is not enough to make you compliant. You will need to ensure the exhaust system you purchased is approved by the California Air Resources Board and bears a CARB EO number. This is the easiest way to avoid being penalized.
Now there are a couple things you need to remember when buying an exhaust for your car. Just because the exhaust system has a CARB EO number does not mean that is 100% it will pass the smog check. There are some CARB approved exhausts which perform great but will always fail smog check, this is something you should consult with the smog technician about. Finally, don’t expect an aftermarket exhaust to live as long as your OEM exhaust system. An aftermarket system can last a long time if it’s made of high quality parts and properly maintained but it will never be as efficient as an OEM system.