My 97 accord gave out pretty large sound when I start the engine, hit the gas, or release it. But when the speed is steady, the sound almost gone. I found this problem yesterday, and I visually check the pipe and muffler, haven't find any hole. Any suggestion what is the problem?

 

leaky gasket or internal hole in the muffler's chambering

 

just because you can't see a hole on the bottom of the exhaust doesn't mean that there isn't one on top or on the side somewhere...anyways, you obviously have a leak somewhere...take it to a muffler or exhaust shop and they can likely fix it for cheap...