So I've been reading and researching about replacing charge pipe with possibly the Perrin charge pipe. Is it true that you don't need a tune if you swap out charge pipes? If so why would you not need a tune since it's allowing more air flow from the co press or side of turbo? I'm nood to WRX and turbos. I'm trying to learn everything I can about my dream car. Been reading books on turbos and engines. Another question I have is eventually down the road I wanted to go stage 2 with TBE. I Live in Massachusetts and have to get car inspected every year. If I go turbo back exhaust that removes the CAT correct. So then I wouldn't be able to pass emissions and inspection correct? So is a stage 2 not possible for me. I plan on getting the Cobb AP with their intake and J-pipe. Any advice and info you guys have and can provide would be great. Once again love being apart of this forum. So much great info and help.