ok so i was driving one day and noticed my exhaust sound a little louder than usualy(no radioanymore) so i popped the hood and found a lot off soot on the block. so i decided to turn the car on and too my surprise i found out that my headers have a crack were the header tubes meet at cyl 3 and 4 before the collector..... my question is how did it happen and why.......they are dc sports 4-2-1 headers on a single cam civic. is it becuz i drive too hard cuz i drive the piss out of it each and everyday w/o a problem. is this a common problem for hondas or what?