to redirect the exhaust flow from the original flow to shorter exhaust flow.
So , like using straight piping without muffler la after the valve open coz the air will go through the new hole.
alo..sori make noise here...
my aircond got prblm...when i wanna topup my aircond,the shop told me that i have to change compressor...as i know,if the compressor konked,there is no blow air right?but my car still...