So about 6 months ago I bought a used 2015 WRX. The car has been having some small issues but nothing crazy. When I first got the car it was pushing 22.1 psi for boost. I reset my battery the other day and noticed that my peak is 12.1 psi. I even tried going through all the gears up to forth and that was all I was able to get out of it. I also have an issue with how the car spikes in rpms and then drops back down and then continues normally. I’ve noticed this issue for about a month now. I’ve asked people I thought would know what’s wrong with it and nothing. No one knows what’s wrong. No engine light, no codes. Wondering if anyone’s had this experience before and how to fix it.