Freelander TD4 injectors diagnostic test results

Hi everybody. This is my first post and I am not expert in TD4 so please forgive me if my description and terminology is not accurate.
I had a problem with my Freeland TD4. It is 2006 model with only 30k on the clock.
It has been serviced regularly.
For few months now the car seems under powered with poor acceleration, when idle it is very shaky. Some times when I start to drive it I have to put my foot completely down and there will be no response from the engine at all, as if the car engine is switched off. When driving RAV seems always between 2-3. Car still reach speed of 80 plus but not very responsive as before. When driving at 30-40 car feels heavy as if hand breaks are on.
I took it to a local garage and the have changed fuel filter, air filter, cleaned EGR valve, and fitted upgraded BMW PCV filter but no improvement then garage advised me to take it to Desial specialist to check injectors. There is no engine warning light and car stars every time with no problem.
I have taken it to Landrover main Delear and they run diagnostic test which came with error codes for MAF sensor and Injector number 2. Dealer seems to think that it is mainly injector problem.
See picture below for injector test results, he said anything over 6.5 is not normal but it only scored 7.1. I have no idea what such numbers mean. The cost for replacing one injector and the MAF sensor is over a thousand pound. I can order and replace the MAF myself but do you thing injector need replacing and is so can I do it myself and where to order one from? And is 7.1 number is very bad?

See attached pictures.

Another picture for all error codes.

Yes no 2 needs replacement or refurbishment then in time looks like no 4 will need doing refurbishment probably the cheapest option

Hi there, mine had a similar problem then the clutch failed but this was my own fault due to trying to tow a heavy van with brakes stuck on. After a new set of injectors, clutch, all clutch hydraulics, a service. The garage also found excessive end float on the crankshaft which was also sorted. Had it back a few days and noticed that it seemed a little sluggish and puffing excessive smoke out exhaust on start up. I put it back in and after a few days they pinned it down to fuel pressure regulator sensor on the fuel rail. If you have not yet sorted it, it might be worth checking out.

G