Engine swap

04 up to 09 I believe have the same engine. Your best bet though would be to get the whole clip. ECU, wiring for the 08. If you have to splice anything and you can avoid that from swapping the whole system. Do you have an automatic? Might make a difference as well.

Be careful. We just swapped an engine and are having trouble getting it to start. If you swap the ECU the key chip code will not match and the computer may enable the anti-theft device. still trying to figure out if swapping in a working engine can cause problems or have conflicts with the ECU.

Am I able to put a Mazda 3 2013 engine 2.5 in a Mazda 3 2008 2.3?????

The 04 is different from 06-09 I believe, there's one small thing the 04-05 has that makes it a difficult swap if you're trying to bolt on the 04 to 06/09 engine. Your best bet is to swap in a 2.5 duratec from a Ford fusion as the fusion uses the same bottom end. Beefier parts, cheaper cost, direct bolt in on a lot of parts while keeping the 2.3 top end to go into the 2.5 bottom. People go this route for stock N/A reliability. Going turbo too? If you need extra help there's a forum on Facebook called Duratec/MZR 2.5 Swap revolution.