Hello and welcome to the forum.
Ideally you need to have the fault codes checked and the live data read from the
,but getting that done tomorrow is unlikely to happen.
As it's going into limp mode it's more than likely a
boost pressure fault,either over-boost,under-boost,or a sensor telling the
that either is happening misleadingly.
I'd start by checking the vacuum pipes to the boost controller and the boost pressure sensor.They can fill up with carbon and cause a similar fault.It would also be worth checking for boost pressure leaks around the pipe work between the
,intercooler and inlet manifold.Check the intercooler it's self too,early ones had a tendency to split/expand although your car is later and should have the updated intercooler fitted to prevent this from happening.
The fact that there is a damaged thread on the
valve isn't ideal,but I doubt that enough boost pressure is leaking from the joint to cause any problems,the other two bolts should hold it in place perfectly fine.