I did basically the same thing to my 2018 STI, (at the recommendation of COBB) added their access port, air intake and downpipe. Then when I looked for a proper map that was supposed to be on the port or their site, I didn’t see one that referred specifically to an intake + downpipe. I contacted COBB and was told that to run both intake and Dp would require a (stage 3) $1600 fueling upgrade. Additionally no maps were available for the changes (they initially suggested). I am running a stage 2 hwy tune and it seems fine, but if there’s a better map that once was in circulation I would love to know its ID. (I am not interested in going to stage 3.) Otherwise I may have to go back to the stock intake, if the current setup is potentially damaging as COBB inferred. Any information on any of this would be much appreciated. I really was impressed by the cob hardware but I’m not too happy with their inconsistent advice.