2000 Ford Mustang sounds like an old, rusty, lawn mower all of a sudden!?

Question

I was on my way to work this morning, and at a stop sign, the light turns green, and I hit the gas, and I suddenly hear this loud lawn-mower type noise. This has never happened before. It's very loud, almost like a huge truck! It's only when I hit the gas or when I am in park. What could this be. I am pretty sure it is not the muffler.

I briefly talked to my friend who also has a Mustang, an 01', she told me this happened to her, and she said it was something that is illegal to mess with? She told me the name of it but I forgot! This is very urgent. She said this happened to her before and her father drilled a hole into something, which made the noise go away! I am clueless.

Answer 1

It could be the Catalytic converter. Inside these environmentally friendly muffler companions is a piece of material that changes unburnt gas and other pollutants into less harmful exhaust by chemically reacting with them. The exhaust then travels through the muffler. After awhile this material that reacts with the exhaust begins to disintegrate to a point that it begins rattling around inside the converter. A simple but illegal solution is to hallow out the converter and let the pieces fall out and simply re install it. This is against the law mind you, and no certified mechanic will do it. Or you could buy a new converter.
If you have a loss of power with this noise, then there is a different problem all together.

Answer 2

A few things come to mind:

1. The exhaust manifold gasket

2. The O2 sensor fell out

3. Hole in exhaust pipe

4. Hole in Catalytic Convertor

5. Hole in muffler

6. Pipe broke where connected to the exhaust manifold

You need to have it looked at since the exhaust gases can burn a hole in something else like your floor carpeting or something else under the hood.

Good Luck!

Answer 3

DPFE SENSOR I'm guessing that is what it is . it is a common problem with for , the website below shows a pic of it , there is two small hoses , one comes off when plugged , and makes a bad exhaust sound , the sensor is about $75 and is easy to change