Reduced power mode V60 D4 2016
 

First time posting and new to the forum. So I've had the reduced power mode come on a few times now no engine management light and it literally flicks on cuts my power then goes again. This is only when needing to climb a hill or boost the car to overtake. I have had 3 diagnostic checks 2 have come up as a injector issue yet the garage doest think it's that? I'm now stuck on where to turn. Any advice from here would be extremely grateful