I will check the connections before I send it to the shop. And if they say that I need to replace the injectors, I'll ask them to recode once again. even though I think that these are siemens piezo injectors.
yes there is one good workshop that repairs and checks injectors. I will take them out (hopefully next month since I'm very busy these days) and get them checked. I will post a follow-up to let everybody know how will it go, maybe I'll help somebody with the same or at least similar problem.
Thank you for all your replies Jamie, I really appreciate it.
thanks Jamie you are being helpful and I thank you.
I forgot to mention in the earlier post the knocking bit. It is sort of a diesel knocking sound it's just more loud than normal. I'm not sure if I'm explaining it right. For sure if nothing was wrong the comp wouldn't point to any errors.
I also thought that the best solution would be for me to take out the injectors, get them checked and then when I refit them, change the copper sealing's, plastic brushes, and the rubber high pressure pipes.