I forgot to say, its pointless having that strut on when its not bolted in bolt it in or take it out lol must be the PCV, as for the jerky thing have you tightend the pcv pipe properly could be unfiltered air getting in thats why its jerking x2 could also be your burning oil via stem seals, drive it on low revs and see how she goes with regards to oil consumption as i/we noticed at the meet when you left you rev`d to pretty much the redline which doesnt help whatsoever........if it still does it change to heavier weight oil and start thinking of that conversion.