So something similar has just started to arise in my msp. The other day I put back in my boost gauge because the car was having problems holding boost and what not. So I fixed a few leaks in vacuum lines and it held steady at 5psi, which it was set at this winter. I have no mods to speak of and all of a sudden the other night I jumped on it in 1st and INFINITE BOOST (ugh) I think it got to 16psi. Well then I let out and cruised through second to third and got on it again to check and see if the problem was bad and by god another 16psi top out.
My first conclusion was vacuum to the wastegate had to be off, only way to run infinite boost. I checked all the vacuum lines and such and no problems. I even replaced all of the lines around the turbo and to the wastegate. Weird thing now is though all of a sudden it is not running all over, it is sticking to 11psi then falling to 7psi. The boost gets higher through the gears on a roll. We then put a JoeP on to see if we could not regulate the problem. And of course forgeting about how poor and unreliable the JOEP really is we still had spike problems but dwindling. So now I am stuck and am thinking the accuator is stuck open.
There are ways to fix it if its a slow opening accuator problem. I believe you can just put some washers on the bottom side of the accuator to get it to close a little faster.
I guess one option if the wg is screwed, why not go external at this point.
WTF..............I am completely lost. Might as well be time to (stoned)
New 2025 CX-5 with highway vibration problem; tires?