Engine light wont go off

Greetings everyone,
2008 Defender puma, which has had the engine light on for a year now.
It went through the EGR valve cleaning for a while, then it crawled and black smoke occured when cold, and now runs just perfect.
It’s that time again to ask for help.
My engine light is on and I can’t pass besiktning.
I cleaned the MAP sensor, also the one by the air filter as well but no change.
I tried removing the EGR valve and when I reached the 4th screw it simply would not catch, it seems it is worns around the edges!
I do have a bit of whistle sound when pushing but nothing major and can’t see any leakes around turbo.
I do see some leak on the MAP unit and retightend everything after cleaning.
All hoses seems fine.
I of course bought a OBD to reset the engine light but besiktinig people turned it back on!
Any ideas whatelse I can do?
Many thanks for your help!