I'm just going to get straight to it. I am 19 years old with a B8.5, I don't know a lot about cars to be honest only how to maintain them and keep them in good condition. I am stage 1+ Unitronic as of right now and I was looking to go stage 3 dual pulley with APR CPS. A bunch of people are telling me to do it and a lot of people are telling me not to. The only reason I have been told not to is bc "I dont know what I am getting into". This is somewhat true as I dont know much about these cars but I want that power!! What does everyone think? What do I NEED to KNOW when going dual pulley? I have read sooooo sooo many threads on this. Only thing I can't wrap my head around is the cats and the 02 censors. Please let me know what you think, what you know and also so advice/suggestions. Thanks!