Thanks for the replies

Happy it sounds like a maintenance thing rather than imminent major failure.
Spark plugs are good I did those not long ago (and it didn't change the problem), but the rest yeh, never to my knowledge.
It doesn't feel like a boost leak, it's feels so "electronic", but of course I could easily be wrong, I'm not an expert. But the injectors is interesting because there is also a sporadic misfire at idle actually, and I've always wondered if that's a lazy injector. I'll have to look into the crank sensor as well.