Hi jk, the problem has actually sorted itself!
I did take the air intake apart and the air filter, cleaned everything up whilst I was giving the engine bay a good clean, but nothing else. A tank full of ultimate diesel and a couple of days with a heavy right foot, and the problem was cured
It might still be an issue with the MAF, possibly just dirty. I will get it looked at properly next time the car is in the mechanics, but for now I'm leaving well alone
