If it's catless without codes it definitely has some sort of tune. I'm not sure how it would work if it's married to an ap, I'm not sure if you can reflash it or not. But if it was open-source it's super easy to pull the flash to see what was changed in the tune. Thankfully, there's a tone of resources related to subaru tuning so I would just search up subaru tuning guides or on romraider.com to get more information. It's a bit intimidating at first but once you get your stuff set up and understand the basics, it's not bad at all.
I would recommend getting a general VAG-COM KKL 409.1 cable from Amazon or elsewhere to start or go ahead with a openport 2.0 but they are a bit pricey. Either way since it's tuned there's no easy way to tell what's going on without logging some data on it
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