The common custom of Sephardim is to do kaparot before Yom Kippur. This is despite the Shulchan Aruch discouraging the practice (O''C 605:1):
מה שנוהגים לעשות כפרה בערב יום כיפורים לשחוט תרנגול על כל בן זכר ולומר עליו פסוקים, יש למנוע המנהג
Those whose custom is to do kaparot on Erev Yom Kippur by slaughtering a chicken for every male son and say verses on it - should stop this custom.
This is opposed to the Rema, who approves of the Ashkenazic custom.
Why do Sephardim who rely on the Shulchan Aruch as the final halacha break from his words and do kaparot?