IMP does not owerwrite
‘FUNCTION’,'PACKAGE’,'PROCEDURE’,'SEQUENCE’,
‘SYNONYM’,'VIEW’,'TRIGGER’ (CODE DATABASE)
Import does not replace codes, to be able to create codes only way is to drop related objects or drop and recreate user then start import.
Link below show a way to to this.
P.S: if you have objects created like “object_name” you have to drop them with using quatations
because they are case sensitive.