I will strongly recommend that you invest 100 bucks in a diagnose kit from Mercedes Benz Owners Best Source for D.I.Y Repairs, Diagnostics, and Quick Fix / Kit Solutions | MercedesSource.com. It comes with everything you need to make it do what is supposed to do. Though is known that there is a lot about the restriction orifices, specially if you already did make sure that the modulator is at the right pressure. He recommends to start for the engine, it will affect the shifting a lot man, specially if the injection is not happening properly. I would say for now that you should buy that kit, read it to understand the logic of how it works related to the engine performance and then start tweaking. I can tell you that it made a world of difference in my car even though shops wanted to replace the whole tranny. I will say it again, buy it!
https://mercedessource.com/search/s...nsmission+Ultimate+Diagnostic+and+Tuning+Kit+