Boost problem

[TomKat99]

Sorry about size of photos. I've done it on the phone.

Took my car to a rolling road. They very quickly realised my aby was over boosting. We disconnected the boost solenoid and the boost came in much lower. They told me they think the solenoid needed replacing.

I thought I've read somewhere if you disconnect the solenoid, the boost should be around .4 bar. So if this is true has the wastegate been adjusted?

[prj]

Yes, it needs to be 0.4 bar unless you have a custom remap specifically for it.
And this is exactly how your car will behave if spring boost is higher than the car is mapped for.

Set it back to 0.4 bar and your car will stop overboosting and oscillating like this.
If your wastegate is untapped, then it's likely the spring has been changed.