Anyone ever heard of the chambers rusting out on a flowmaster? I put an offroad x pipe on my mustang that already had 2 chamber flowmasters and it sounded like a straight pipe. I went yesterday and had another brand muffler welded in place of the flows. After the flowmasters were off the car I looked inside and you could see straight through from inlet to outlet. Also noticable were what was left of the chamber walls - just a small amount at the top and the bottom. I do not know how old they are since they were on the car when I purchased it about six months ago. Is this common with flowmasters? No one that I know has ever heard of it happening. Anyone have any thoughts?