547.604. MUFFLER REQUIRED. (a) A motor vehicle shall be equipped with a muffler in good working condition that continually operates to prevent excessive or unusual noise. (b) A person may not use a muffler cutout, bypass, or similar device on a motor vehicle.
MANY diesels do that since there is a turbo to 'somewhat' muffle the sound...
but just roll down your window and listen to the 4 cylinder ricers and how pitiful most sound with their little fart cans sticking out of the back...
And nothing sounds as 'wanna be but not there' as a six cylinder chevy pickup without mufflers !!!!
but depending on your engine, you may benefit from a mellow sounding flow through muffler like the walker big truck muffler...
We put magnaflows on the wife's Audi 4 cylinder turbo, but they are very sedate, just enough to give it a LITTLE rumble, but not 'noise' !
I would not run straight pipes. You are not going to gain any power. I have a 5.4 with no cat, and the only reason it is currently running without one is mine was clogged.
Mine sounds raspy when I get on it. It has a magnaflow muffler on it.
I can't imagine how bad it would sound without the muffler on it.
As others have stated, it is illegal. You can be fined for it. Until I get my aftermarket cat on mine, I am always aware when I am sitting near a leo and take it real easy on the gas when pulling away from him.
They are loud without cats, I imagine deafening without a muffler.
I am sure Texas has many more Harley's w/o mufflers as the state of CT. If those are legal then why not a truck?
I'm pretty sure motorcycles would be covered under that law as well, and therefore required to have a muffler. It's more a matter of enforcement. It's pretty much accepted that Harleys are loud, so cops tend to look the other way.
You could probably run straight pipes and get away with it if you were smart about it. Problem is most guys do it just for the sake of being loud, so they go around revving it just to make noise. This is sure to attract a cop's attention and get you a ticket. The exhaust on my old truck wad obnoxiously loud and I never got any tickets for it. I did get a ticket for bumper height, but they didn't say anything about my exhaust. On the other hand, I have friends that have had more than one loud exhaust ticket and theirs wasn't nearly as loud as mine was.
Here in The Great State of Texas, the turbo counts as a muffler as it tecnically "muffles" the sound of the exhaust. That's why all the Cummins folks get away with straight piping their trucks and making enough noise to wake the dead.
Unless you're a 2008 and newer truck, you don't get any flak for it at inspection time in Texas. All they do is drive it, look at it, make sure your lights work, put a new sticker on, take their $12.50, and that's it. They don't even bother looking below the truck...
It works a little differently in VA. Here you technically can't alter the exhaust from OEM or equivalent to OEM. You can't do anything that alters the sound level, the back pressure, or the emissions from the truck. If it's a single exhaust from the factory, it's supposed to stay single if / when it's replaced.
There are several ways you can get nailed....... Vehicle code sections that....
1. Prohibits removal of the muffler
2. Sound dbs (there are max levels depending on year of vehicle established in federal regs that states adopt)
3. EPA regas- yeah, mufflers are considered part of the smog system
So any law enforcement, smog inspector, or AQMD officer could cite you.
Now for reality, IMHO, on my previous F150 (1990- that I had until 2006), Fords cats absorb about 70% of the sound, I ran striaght tailpipes right off the cats- now mind you I have the 300 cid 6 with 5 speed.....but it was quiet at idle and even when reved under load it sounded like a small block V8- and was never questioned about it even at the smog test. On my current 5.4, I was very close to doing the same thing....but it had just a little more "brap" than what I cared for so I threw on 2 Allied resonators (glasspack straight through) units- in terms of noise level (db's) almost no change to the human ear, just took out the "sharp braps" but left a very deep rumble on acell/decel.