Recently I noticed that when I accelerate from a stop I can hear some rattling from the rear of my 94 Civic Hatch. I have not had time to lift the car up and look underneath, but I did notice that when I hit the muffler there seems to be little things in there that are loose. I am assuming that this is causing the rattle. Sounds like little rocks, but I am not sure how rocks could get inside it. I'm wondering if it could be from the cat or if the muffler could be falling apart from the inside, since it is the original stock muffler. There does not appear to be any visual rust and the muffler looks good, but you can never tell. My gas mileage does not appear to be going down and I do not smell any sulfur, nor any check engine lights, so I do not think it is the cat. Any ideas? I will eventually take the muffler off, but with a busy work schedule it looks like that may be weeks from now.

 

The condensation/water created from the combustion process causes the internal baffles of the muffler to be subjected to moisture. This results in the baffles to rust apart and deteriorate, sitting loose inside your muffler. My '95 did the same thing, just before the bottom rotted out when the drain hole got rusted closed. Sounds to me like it is time to replace your muffler.

 

Thank you Cody, I was thinking that the muffler has to be replaced. Time to start looking for one!

Much appreciated.

 

No problem! This is the benefit of a good forum, sharing thoughts and past experiences. I bought my exhaust muffler through RockAuto, bought the Walker brand - reputable name and am happy with it. I opted for the stock muffler.