I have no idea what's wrong with my car. It's stock in every sense with a stage 1 93 tune. If I'm just costing at 20mph and let off and wait till the engine rpm gets to its lowest point around 1k rpm then blip the throttle I'm getting feedback knock. I had my knock sum on there, and it was jumping up in count & my feedback knock values went to -1, -2, -3..... I also had feedback knock when driving at 60 in 5th gear, downshifted to 4th and was holding the throttle around 3k rpm to speed up and I got a -4 on the feedback knock value. What's going on? What should I check? What usually causes feedback knock on Subaru turbo's, this is my first Subaru, first turbocharged engine, first Awd car. Please someone give me an idea what to do to fix this issue.
Edit: also my knock sum is at crazy numbers just after a 7 min drive it said 26... and just blipping the throttle as stated above it was jumping up in like intervals of 2 or more. There isn't any audible noise, and power doesn't change at all throughout the rev range in fact it's actually stronger than before now that it's tuned. And I'm not sure if this makes a difference but it's the 5EAT transmission. If you need any more info ask and I'll provide