thanks for the mention
there are a few known issues to check for free ones first
look on the top of the inlet manifold , for swirl flap bar , is one there (if alloy manifold)if not it might have fallen off. if plastic manifold nothing to see, swirl flaps are built into the alloy block nearest head.
second whilst logging while its doing its bad idle , stress each injector plug in turn to see if sound or value changes push pull twist gently on loom to plug.
if nothing changes ,move on, if it does look into loom plug repair kit like this from alfa or Vauxhall specialists(usually number 3 plug from what ive seen historically on web vectras were worst)
http://newalfaparts.co.uk/diesel-19-jtd-/441-diesel-injector-wiring-repair-kit.html
next engine off and disconnect each plug in turn and spray electrical contact cleaner in both halves and reconnect the plug several times in out to clean contacts, remove again and spray again, shake out excess and let dry, then reconnect and move to next plug.
next id be adding a strong quality injector cleaner like ar6400-cr or bg244, it will clean any build ups from fuel system from pump regulator and injectors and ensure its as clean as can be if you eventually move on to injector swaps you don't want crap getting into your expensive new injectors.
the codes need sorting , ask if anyone close has fes and willing to recode them correctly, the codes are on the injector solenoid tops, also be sure other codes are correct as may be in wrong cylinders etc if played around with.
values should be +/-0.9mm3 or even +/-0.6mm3 maybe for the jtdm I tend to check at start up and when warm the values will always be higher when cold.
compare like for like values so check now when cold after say 5 mins idle as one test and when upto temp and let idle for a min as another test.
after a tank with cleaner compare like for like tests.
if you still have a working dpf id be also adding a dpf additive to help burn off the dpf at alower temperature and try to give it a good couple of runs at speed/load to allow passive regens.
lastly with history unknown there could be a question of waterpump/cambelt issue and valve train damage, seen a few issues where after a cambelt failure the cam pullys have worn/damaged the timing key to shaft so cam timing has been out when rebuilt.(worst case not likely but something to bear in mind)
after each job id recheck values to pinpoint what issue was causing what.
also bear in mind injector correction value can be physical engine issues like rings , valves etc and not related to injectors at all.
your knocking sounds injector related though unless maybe could be sticky hydraulic follower or something like that(worth a treatment before next oil change)
some things to work through for now for you.
