Start with general maintenance, dsm=don't stop maintaining. When ever I do a repair I look at what's in the area while I'm in there if it looks worse than id like I replace it. When I got my car i started with a tune up I found my throttle body only opend 85% of what it should.
Found this helpful when I did it.
https://m.youtube.com/watch?t=9s&v=TccGNg-vb8g

Start here, and stay out of boost until everything on here is performed.

http://www.dsmtuners.com/threads/dsm-maintenance-guide.476550/