Hallo, im reading this post with interest, because I have exactly the same problem with my van, 2016, 2.2 . Went to several dealers,
First a got code 2599 and 2598 .then the replaced sensors map, maf, intercooler,
Code was still comming then the cleaned dpg filter, this was not necessary he told me after,
Now they fitted a complete new turbo unit,and after 30km I get p0299.
When I turn the key the code is gone and I can drive approximately another 30km .when the engine is cold in the morning it comes on for about 5 or 6 times and then I can drive for about 30km , it's everytime p 0299 . It cost me a lot of money and irritating so far, can anyone help me thx