Breathing system of engine is helpful in escaping hot gases from crankcase which r produce during combustion reaction..if ur engines is breathng system is not working good r its been blocked or chocked then ur crankcase will b pressurized and this pressure will cause to oil leakage frm engine seals etc...
Hot mobile oil vaoprs also escape frm this breathing system
here is the pic before breather filter

after stock filter manifold is removed
