What does cut out open mean??

 

a cut out is a bypass for the exhaust system just before the catalytic converter. Opening a cut out makes the path of least resistance for the exhaust flow go directly to the atmosphere, it no longer travels through the exhaust pipes, cat-con, mufflers, resonators.

It is very loud and very illegal for non-race track use.

 

here is a diagram from QTP they are supporting members on this board.

 

Definitely a great explanation.