In short, straight pipes are not legal in the United States. Most states impose an exhaust noise limit that prevents the use of straight pipes. A few states, like New Hampshire, even have explicit laws against straight piping your vehicle.
Having said that, you can still install a straight pipe and have absolutely no issues. As long as you don’t use the loudest pipe, don’t produce black smoke, and drive carefully, you can get by even with a straight piped ride.
So the straight pipe is illegal (and sort of legal), but does that apply equally to cars and trucks? Continue reading to find out.

Is It Legal To Straight Pipe Your Car?
Unfortunately, the same goes for cars.
The annual inspection of your car’s emissions is mandatory. There is little chance of passing inspection with a straight pipe in the exhaust system. Moreover, you cannot insure or register your vehicle if you fail the test.
Is It Illegal To Straight Pipe A Truck?
Similar to cars, trucks are not exempt from the illegal straight pipe law.
The problem with a truck is that it emits a great deal of black smoke sometimes due to the pipe. In terms of noise, it is far worse than cars.
Most states also mandate trucks to have a fully functioning exhaust system and muffler. A straight piped vehicle will not meet these requirements. Hence, I have to conclude that it is not legal to straight pipe your truck.
How about other trucks?
Is straight piping a diesel truck legal?
The answer still remains no. The rule, as mentioned earlier, also applies to diesel trucks.
Nonetheless, if you are interested in straight piping your diesel truck, you can read my instructions by clicking here.
Why Are Straight Pipe Exhausts Illegal?
Wondering why states disallow straight pipes? Here are three reasons.
- Noise:
The sound of a straight pipe can be unbearable at times. While some motorheads love it, the loud noise can be inconvenient for those near the vehicle.
For this reason, some laws set noise limits. It varies from 70 to 95 dB depending on the area. You cannot exceed the decibel limit while driving at a particular location.
- Emission Test:
Many stock components such as DPF along with the muffler are removed while straight piping. Without them, it is almost impossible to pass the emissions test. This is one of the crucial reasons states do not legalize straight pipes.
Related: Can you pass inspection with a straight pipe?
- Smoke:
A straight-piped car or truck can occasionally blow a lot of smoke. It is illegal to operate such a vehicle in most states; the smoke is unhealthy to nearby residents and causes air pollution.
Where Is Straight Pipe Legal?
There is not a single state that specifically permits straight pipes in vehicles. However, some territories are more tolerant of straight pipe, while others strictly prohibit its use.
The following is a brief breakdown of the laws in various states based on the region regarding straight piping your vehicle.
1. Northeast Region
Is Straight Pipe Legal In New York?
In the same way, as in other states, the New York Consolidated Laws prohibit the use of straight pipes for a variety of reasons, including high noise.
In fact, the law mandates a sound limit of 76 dB for vehicles going 35 mph or less and 82 dB for those going over 35 mph.
Is Straight Pipe Legal In NJ?
The New Jersey law regarding straight piping a truck or car is precisely the same as the Alabama law, which says your vehicle can’t make loud noises. As a result, the straight pipe is not legal in NJ.
Is Straight Pipe Legal In PA?
Since nothing related to the straight pipe appears in 75 Pennsylvania Statutes, it is safe to assume it is legal. There is, however, a noise limit.
Depending on your vehicle and location, you need to maintain a decibel level of 78 to 92.
2. South Region
Is Straight Pipe Legal In NC?
According to the General Statute of North Carolina, cars must have a stock exhaust system (e.g., muffler), and it has to function properly. Therefore, straight piping the exhaust is not legal in NC.
Is It Illegal To Straight Pipe Your Car In Florida?
You cannot use a muffler cutout or similar devices in Florida, meaning straight pipes are also illegal.
Is Straight Pipe Legal In Virginia?
Virginia is one of the states that oppose straight pipe construction strictly. It is clearly prohibited by Virginia Code to use ‘straight exhausts.’
Is Straight Pipe Legal In Alabama?
According to the Code of Alabama, vehicles must have fully functional exhaust devices. Thus, installation of the straight pipe is not allowed.
Is Straight Pipe Legal In Tennessee?
The Tennessee Code says it is unlawful for a vehicle not to have a properly working muffler. It implies straight pipe is illegal in Tennessee.
Is Straight Pipe Legal In Texas?
The Texas Code expressly prohibits the use of devices like muffler cutouts and bypasses, making the use of straight pipes illegal.
Is Straight Pipe Legal In Oklahoma?
The Oklahoma Statutes forbid any modification of the exhaust system. Since you cannot straight pipe a vehicle without modifying the exhaust, it is not legal in Oklahoma.
3. Midwest Region
Is Straight Pipe Legal In Ohio?
The Ohio Revised Code says that motor cars should not be equipped with devices that generate excessive smoke. Since straight pipes produce such smoke, they are illegal in Ohio.
Is Straight Pipe Legal In Michigan?
Under the Michigan Compiled Law, vehicles should have exhaust systems that prevent unusual noises. This may allow you to use a straight piped car, but be careful about the sound.
Is Straight Pipe Legal In Illinois?
You cannot use any type of device like a straight pipe that amplifies the sound of a vehicle. If you do this, you violate the Illinois Vehicle Code since straight pipe is illegal in the state.
4. West Region
Is It Illegal To Straight Pipe A Car In California?
According to the California Vehicle Code, it is against the law to modify exhausts or install cutout devices. It indicates you cannot legally straight pipe your car in California.
Is Straight Pipe Legal In Arizona?
As per Arizona Revised Statutes, those who use devices like straight pipes or cutouts are subject to civil penalties. In other words, installing straight pipes is not legal in Arizona.
Is Straight Pipe Legal In Nevada?
Vehicles cannot have muffler cutouts or any other components that can produce excessive fumes, as per Nevada Revised Statutes. The straight pipe certainly falls into both categories, so it is illegal.
Is Straight Pipe Legal In Oregon?
The Oregon Revised Statutes require your vehicle to meet noise emission standards. This is not possible with a straight pipe. Therefore, it is not legal in Oregon.
To Sum Up
From the article, it is apparent that straight pipes are illegal for most uses. However, if you can tone down the noise and keep the smoke at a reasonable level, it is unlikely you will get into trouble for it.