So I know I have to replace the center muffler in my LX, so I was under there looking at the flex pipe and rear muffler to see if they needed to be replaced too, while I was under there. I noticed that half my gas tank seems to have what kind of looks like soot on it, but only half. It's kind of behind the flex in the flex pipe, but I can't see any crack in that pipe. It's dry, doesn't look like oil either.