Hey guys, my 05 alloytec vz Calais when cruising at 100 on the highway if I drop it down to 80 or so and then accelerate lightly it will struggle and a slight sorta vibration, and my revs will drop, very sluggish, I have to really give it a bit to get the revs to 2000 or over. I have checked transmission oil, all good. Anyone have any idea at all?? Someone said could be transmission ecu?