Engine noise
 

My car has just started making a lot of noise 3 days ago. It has a vibrating type noise. Does it have anything to do with the muffler? I don't think it has anything to do with the actual engine. Everything sounds fine on idle. It's when I acclerate it sounds really rough and loud. I don't like it and it makes my car sound like it's going fast at 10 miles per hour. That's how loud it is now. It never was like that. I have a 1996 Mazda Protege

It could be some part of your exhaust system. The closer it is to the engine, the louder it will be. I had a pipe fall off on me right as I came off of the highway, and my car sounded as loud as NASCAR. Try to bring to an exhaust shop for an estimate, and see what they will tell you.