Your throttle actuator may need to be replaced due to the "Fuel Safety Shutoff" codes. Before going any further with the plug and play diagnostics I might suggest having a fuel volume test perfomed. Cylinders one and six will be the first to suffer when the fuel volume drops causing the 2 cylinders to run lean. When do you need fuel volume the most, under a hard throttle condition. IMHO-A fuel pressure test is always followed by a fuel volume test, 1-ltr in approx 25 seconds on most MBs.

Pop the fuel rail out and swap injector 6 with injector 3, if there is an issue with injector 6 the problem will move to number 3

Have the fuel pump volume checked...........if it is determined that it can not be the "cause" of your complaint other diagnostics will be needed We'll do what we can to help you avoid opening your wallet too wide to address this matter