2015 ST3 Focus ST
So the past few days I've been having some trouble with my ignition corrections dipping real low at WOT and the farthest I've seen her at was around -5.75. I've attached a data log from today where I dip into the 4's. At this time I was on 89 and completely stock, installed new motorcraft plugs less then 200 miles ago all gapped at .32. My question is whether or not this is a serious problem and what steps I should take to find a cause. I constantly watch my APv3, AFR is good right round 11 at WOT. I've also read on here low quality fuel can cause ignitions corrections to hit negatives so today I tried to empty the tank and the filled up with 91 from a chevron. Any tips or advice is greatly welcomed.