Hi I have a 2001 E320 cdi. During the last years had boost issues, black smoke(in huge amounts) and finally before 3 months the car could not accelerate. Scanner showed EGR, kick-down switch and throttle position sensor errors. I cleaned the EGR (it was completely blocked), I replaced the throttle position sensor and checked the kick-down switch (was fine). Nothing changed. I made the EGR cancellation and smoke was reduced but still no boost and got the same errors.We did star scan and showed EGR and throttle position sensor. The technician suggested to replace the vacuum pressure converter. After replacing it the car seemed to accelerate much better and kickdown worked but without boost. Finally I got a used but in good condition egr and after cleaning and testing with the mechanic i installed it. All errors went off except the EGR. Connected to the star the technician tested egr manually using a hand pump and worked fine (we engaged the turbo also). Flap motor also works. So the suggestion was that there might be a leak on vacuum tubes. I replaced them with new and I also bypassed the long one that connects the EGR to the turbo line. I still get EGR error, the car accelerates much better but turbo is not engaging due to EGR error. Smoke is less. Acceleration is steady and all gear changes are st 3700 rpm. Any suggestion? Star shows that airflow is lower that the required. The only part I haven't change is the MAP sensor.