Why You Shouldn’t Change Your Car’s Muffler

Hi everyone, I’m Andy Shane and today I’m going to talk about why you shouldn’t change the muffler on your Jeep and explain why. You have the best exhaust system for a Jeep Wrangler, but why would you want to change the muffler?

We’re having a little history lesson. In 1897 the Reeves Brothers of Columbus Indiana patented the first modern engine muffler system, now mufflers do exactly what their name says they mute the sound, make it quieter so the engines aren’t loud and uncomfortable.

Sound

Here’s Lexus, if you turn it up a little, turn it up, okay, it’s about 40 decibels, not that loud, and here’s a bike that has no mufflers, it’s a racing setup, they look like mufflers but there’s nothing in it, that’s 110 decibels, and on a decibel diagram, the Lexus is quieter than a speaking voice, while the motorcycle, hey, it’s almost as loud as a pile driver up there, that’s 112.

So when everyone with all their vehicles hit the muffler’s take-off and either straight pipes with no mufflers or a fake muffler with no baffles inside, it would be really noisy outside. Yes, mufflers limit an engine’s performance a bit because they limit the speed of the exhaust. But if you’ve ever driven on a racetrack and man, you couldn’t hear for a few days.

I mean these babies are loud and I know a lot of young people especially in Japanese cars, they take their mufflers off, throw them away and they put on those little free-flow mufflers that kind of sound like that Bees as they drive down the street. If you listen carefully to many of them, you will hear that they don’t sound like they are right run.

That’s because they don’t run properly like their cars were made to run properly with the muffler system running the gas at a certain speed, the oxygen sensor measures how much residual oxygen is in the system, they store some of that oxygen in the catalytic converter, and if you remove the muffler and let the system flow much faster it can mess up the emission control system, including the air-to-fuel ratio that the computer gives the injectors, and they can actually run worse if you take off the original muffler.

Software

Now I have to say that the Mustang I just tested has a great sound but guess this baby was designed by engineers who spent a lot of time on it has to make the sound you want, have it work with the anti-pollution system to make it legal, etc. nd even to pass the decibel levels, there are certain levels that cars have to sell in the United States.

Now I know people are going to say, Andy, you’re a hypocrite, your bike over there, hey, you got the mufflers off but hey I have some fancy software in a computer, it’s not American motorcycle, so there was a great website where I could just download different patches for the exhaust and the computer Reprogram it to run perfectly.

That’s why I see so many guys driving around on Harleys that backfire, and sometimes even Ferraris that backfire, they change the exhaust system, but they don’t reprogram it to run properly so they run really bad even though they make a lot of noise, hey, they don’t run right and that’s not what you want, a loud car that isn’t right.

When I was a young mechanic, it wasn’t that difficult to change the muffler and put in a free-flowing system because they had carburetors, they had jets that let more or less fuel and airflow in, and you could re-jet the carburetors to compensate for a free-flowing exhaust, anyone with some time and a little imagination could do it, but modern cars they are all fuel injection, they have air to fuel ratio sensors which are very sensitive.

Not only can you change the car’s exhaust system, even putting in a free-flow or muffler will mess with all of the computer software and the check engine light will come on, they won’t run properly, you will get worse fuel economy so it’s not a smart one thing if you’re just planning on making a little noise in your car, and really even if you have all the equipment.