I recently bought a 2012 Subaru Wrx and have had it for about a month now with just under 100k on the odometer. I bought it from a Subaru dealer and they had said nothing of a CEL coming on or any issue. I got my first code within the first week of owning it and driving it around. It popped up and was just a cylinder 3 misfire, but I did not notice a lack in power or a stutter of any kind when the car threw the code. I just simply turned it on and let it warm up and idle and it popped up. I cleared the code bc I thought it just read something funny upon the start-up since it was a cold start-up and it didn't throw a code for another week or so and then it was again cylinder 3 so I did the same and I filled up at a gas station with 92 fuel and always put premium in my tank upon fillup. I get another code and it says misfire on cylinder 1 and 3 so I pulled the plugs out and just did all the plugs with NGK Iridium plugs, just before I did plugs I got that code for cylinder 1 and 3. After I cleared it my car would not idle, it would go all the way down to just about stalling out or stall out when you would start it up, I then used the method to recalibrate the throttle body which is just letting the battery sit, disconnected and turning the car on and off for 10 or 5 minutes without touching anything and just letting it idle and that fixed the idle situation. I have talked to a few other owners and whenever they get a code and clear it, they have no issue upon starting up afterward so idk what that means. But, I changed plugs, recalibrated the throttle body, saw on another forum that the wiring harness can be bad around the connector for the engine by the turbo and I wiggled that and nothing seemed to happen, no shaky idle or misfire. Then I was driving around yesterday after recently changing plugs and having no codes, I got another CEL and I checked it and it says a misfire on cylinder 1,2, and 3 and I notice no loss in power, no hesitation while I go up in rpm, it does dip in rpm while idling sometimes but then sits at about 700 to 800 rpm 95% of the time and all plugs came out dry and had nothing weird happening, also cleaned MAF and didn't help, the code came back within a day or two. Does anyone have any suggestions that I could check for besides dropping it off at a shop or throwing parts at it?