#2.5x

So I recently got a 2012 forester 2.5x with 145000 miles. I’ve been getting 2 codes. One code is a p0420 which is a Catalyst code. The second code that is giving me the most problem is a p0302. So I got this code about a month ago and replaced the ignition coil and spark plug(when I took out...

I’m new to cars and this forum so forgive me if they’re is a previous thread (and if there is point me in that direction) but I recently bought a 2.5x llbean I wanna do a Sti swap was told by my brother it would only work if I have a XT model? Is it just easier with the xt or what’s the deal id...