Ok, so me and a friend of mine replaced a muffler on my car yesterday and went for a test drive with it after. Everything was fine cept I heard alittle scraping so I figured one of the tailpipes was just hitting something. So I crawled under there today and it was hitting so I loosend the u bolts bent it back and tightend it and made sure nothing else was hitting. And now ITS STILL MAKING THE NOISE!!! I went under again and made 150% sure that nothing was touching, it sounds like a tinging noise from the muffler. Anyone had this problem before? Maybe it needs to break itself in or something like that