Hello,

When replacing the wastegate actuator hose, I prefer to use fuel-line hose. (fuel injection hose is ribbed and is much thicker and stronger, so that this problem doesn't recurr). As to what problems this boost may have caused, I don't know for sure. When the car went into overboost, the computer should have cut fuel and the car should have started bucking very badly (VERY noticable).Did it do this? That hose being broken could be what is causing the bad idle and so on as well. I would try replacing the hose (with fuel hose) first, then go from there.