I would pull off all those extras and run the car back to stock. Hell that could be a stage 2,3,4 unichip map on that thing. Does the car run normaly when you are driving slow? does it idle ok? Did you buy it from a subaru dealer? If the person who trded this car in stepped up to an STi you may want to try to get ahold of him or her and see whats up. That person may also have that other turbo and IC and my sell em to you cheap. I would keep all of the after market stuff until you figure out what you want do with your car. 17.4 is too high. If that car had a bigger turbo it probably had bigger injectors too(maybe). I think you need to check ou the facts on this car a little. Good luck with your new subie and welcome to i-club. Feel free to ask any questions.