I have the stock H-Pipe on the car. I've had the mufflers on the car for about 3 years now and it just started a couple of months ago, and has gotten progressively worse. It's VERY prominent on start up and when in lower rpms, going through each gear. If I lay the hammer down on the accelerator the buzzing stops. I took the drivers side today and you can shake the muffler, and it sounded like there was trash in the muffler. I took water and compressed air to see if I could get it out. SEVERAL pieces of rusted metal washed out of it, but could not get it all out........AND the buzzing was still there when I put it back on.
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