About a year ago I shortened the waste gate actuator arm 5 turns. I did notice a difference in performance (pretty nice). But a few days ago the check engine light came on. I retrieved a 4-1-4 (Turbo boost pressure too high), 4-3-5 (Heated oxygen sensor response response slow), and 1-4-3 (Front knock sensor signal absent or faulty). I backed the arm 5 turns, cleared the codes and drove the car. 4-3-5 and 1-4-3 came back but not 4-1-4. Do any of you think these codes are related? What should I do? The car seems to be running fine. Has anyone else had this problem? Thank you.