Is it easy to fix catalytic converter on 2004 Kia Amanti? Getting 703 error code

Front cats are a job rear cat is not to bad.I don`t see that as a valid code.There are 2 types of converters.Main cat and warm up cat.Make sure you do the right one.We use the Kia oem GDS diagnostic system.I suggest you call us for an appointment to have it correctly diagnosed.