I/we work on a lot of Sprinters --about 4 to 6 per day.
A scan code mention would be helpful, live data outputs best!.
Going by experience and pattern failures your most likely problem is to do with the charge pipe tract to the throttle body..
Try doing a stall test with an assistant listening for the whoosh of charge air escaping.
Most likely places are the dog leg elbow O ring off the turbo,. the silencer O rings and sleeve, the toilet P trap charge hoses to the charge air cooler both sides (they split ) and the joint sealed by a square section O ring at the throttle body. It comes loose
Frankly this is the WORST air charge system I have yet seen on a diesel --Frankly its bitty and its junk. :fail
Also always check the orange sleeve at the turbo inlet tract . MB recommends a change out EVERY time you disturb it. It has sealing problems causing MAF sensor mal functions
If the rig has been running for any length of time then the DPF might be choked up. Anything more than 6 grams of soot/ash. will shut it down due to excessive bank pressure .
This where the scanner comes in useful since the EBP and differential pressures sensor read out might be the real indicator as to what is the problem! Plus drift on the major pressure sensors ! Anything more than 25 HPa will cause the issues you are mentioning.
I hope this is helpful.
Regards
Tuercas Viejas