Re: Protuned? How often do you see knock? What magnitude?
You will always see small amounts of knock correction in the 2015+ platform (both WRX and STi). Subaru revised their knock control strategy for 2015 and made it much more sensitive (which is good). Anything below -3 is fine from our experience. If you are constantly seeing -2.8 under WOT, add some octane to the car and see if it goes away. That will tell you 3 things, poor fuel quality, aggressive tuning or if it is just engine noise.
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377 Worcester Rd, Charlton, MA