i drive a 6.0 chevy 2500hd vortec. a while ago i noticed a hole just after the cat , well today i noticed it got bigger and i could def hear it. will this affect my mpg? or a loss of back pressure? i am thinking of putting on a new cat back system when i save up the money. i have been told to do duel pipes out but i dont like the look and think the single out looks better. anyone have any suggestions?

 

It shouldn't give you any troubles with that hole and i just recommended the flowmaster 10 series. i would prefer true duals but if you don't want that, i have just one muffler and it sounds clean and i highly recommend it.

 

aside from just that annoying exhaust leak sound it wont effect you much. if you are looking for a new exhaust and live somewhere where it snows and the county puts salts or chemicals to take the ice away id reccomend saving the extra cash for a stainless exhaust where i live a normal one is good for maybe 5 years before it looks like a child welded it together i just had to cut out my mufflers and a good portion of pipe and it had probably 5 extra pounds of slag on it haha