u/BirthdayDefiant8950

I just bought a 04 wrx that has a supposed “blown” hg. The oil doesn’t look milky in the slightest and he said it only overheated once when he drove it and then he parked it and I bought it a year later. But anyways. He doesn’t know about any of the parts on it or about wrxs much in general and that’s why he sold it, and I did get some receipts for things from before him, but the car sounds like it runs rough now and I bought a Cobb tuner but now I honestly don’t know where to go or what to do with it lol. Any advice would be appreciated.