Were you only getting the E3 and E4 O2 Sensor adaptation codes? I'm also getting the following; CA and CB O2 Sensor control limit codes.
Prior to replacing the pre-cat O2 sensors, I was also getting a random misfire on all 6 cylinders. Replacing the pre-cat O2 sensors and clearing the codes, the new Bosch O2 sensors took care of the random misfire condition (the pre-cat O2 sensors will lean the mixture too much and can cause the random misfires. I was leaning towards the DISA being the last of my problem and watching those 2 videos seems to confirm my thoughts so I will be ordering a new one so that it is on hand when I remove and inspect the old one (my old DISA has been making some noise so I'm sure it isn't working correctly AND if I clear the 4 codes, I can drive several days until the same 4 codes light the service engine soon light.