Definitely seems like a Dump valve failure again.
I totally lost boost the other day again, after a while a let the car sit for a while and when i restarted it i had full boost again but it was massively struggling

Dealer will replace the valve again i just have to book it back in so thats a + for once from Wessex.
I have e-mailed a few companies to see about replacement DV's tonight though so may just do that and hope there are no more issues.
I'll update this when i know a bit more.
if only.. AGP fault codes can be a bit cryptic 
You are not far wrong there Lloyd
