Thanks mmi, really helpful. I'll have to figure out how to plot these graphs like you do at some point. Other parameteres above feel like results of ecu confusion from the bad sensor data in my mind and from the feel of the drive, ecu over/under fueling around the glitch or bad data it was getting causing jumpiness and engine stutter.
Crank Position Sensor is now changed for a VW OE one. First things I noticed, start took less turns of the engine, sounds smoother just after starting even when cold. Gear changes in auto requiring a downshift under heavy accelerator pedal input from D6 or D7 were quicker and less hesitant.
Took her for a long drive this morning to replicate the 70mph 2000 rpm style of driving in 7th manual that reproduces the glitch. Felt great to me by comparison to many previous journeys, rock solid and no issues over a 45 min drive of about 60 miles. Setup logging as before, but some sort of problem with vcds/my laptop meant it saved the file again with 0kb, slightly annoying I can't share the data on that run so will try again at some point.
As the problem has been so sporadic I will hold out from rejoicing and declaring 100% sure fixed, but already feels like the issue is resolved.
Can't thank you guys enough on this forum. Without you and VCDS testing and that previous T6 post from ben3042 (
204 DSG intermittent momentary power loss), I'd have been wrongly guessing at EGR related problems, (suggested by an ex-BMW mechanic, who changed the wrong sensor, the camshaft position one) for a long time at much higher cost!
Potentialy another win for T6 forum and VCDS and just in time for xmas road trips with the fam.
Best wishes and much thanks.