there are tons of threads on this. do some searching and if you need some more help post a thread with more specifics. i know i have posted this plenty of times.
i believe it was 01.5 they changed some stuff in the focus. if you have a car before than you want to find a donor car from before then. if you have a car newer then that (as you do) then you need a newer donor car.
do some research and make sure it was 01.5
2003 Focus Sedan - Sold but not forgotten
2014 Mustang V6 - Current