Vehicle details:
WDB2100622BXXXXXX
2001
E240
M112 2.6L V6 +-215000 km

I have a rough idle with noticeable misfires.
I connected my OBD2 reader and found code P0305(Cylinder 5 Misfire Detected).
I left the vehicle to idle and checked the values returned by the lambda sensors and noticed voltage dips on the second bank sensor, see attached images. I plotted bank1 Lamda voltage, bank2 lambda voltage and engine RPM, engine temp at 92C.

From the data I assume that there is an injector on bank2 that did not inject fuel as the low voltage registered indicates an oxygen level close to atmosphere. Conversely a spike in voltage would indicate en excess fuel and therefor a faulty coil pack. And from the misfire in cylinder 5 I assume injector 5 is the culprit. I removed the electrical connector to injector 5 and an open circuit fault was immediately stored indicating that the ECU will detect a wiring problem to the injector. My feeling is that injector 5 is at the end of its life causing it to not inject at times and also causing the fluctuations in bank2 lambda sensor voltage. It fluctuates wildly when compared to the bank1 sensors.

Can any one with experience with the ignition system provide insight into my assumptions?

Attached Thumbnails