I was in touch with my Volvo mechanic, and based on symptoms and fault codes, he agreed this sounded like an issue with the throttle body so I am getting that changed tomorrow. I will give an update on the result as soon as I've been able to test the car, as I hate when other leave their threads without any actual resolution.
Also, I mistyped.. the error codes I had was ECM-9130 and ECM-9140, ECM-9150 was never in there.
Other research also suggests that it is indeed the throttle body, and the symptoms are very similar to what I had five years ago which also led to this being changed. Not very durable these things it seems.