Can someone please explain how to locate and disconnect MAF temporarily on a 2001 1.9 JTD, so I can diagnose whether the performance decrease is MAF-related or not?

I really suck at mechanics so details and pics are welcome! I would take it to the dealer however from my past experience whenever I suspected something and mentioned it to them, they changed (and heavily charged) this part, so now I'm trying to have some sort of idea on what's wrong before being plucked again.

The symptoms are basically reduced power/performance across the entire rev range, turbo is working (I can feel a slight kick but not as before).

Thanks!

Looking down onto the top of the air box which is just in front and below the battery you should see this;



Unplug the plug as shown and it's done.

Cheers Decron, you are a true gentleman and mechanic