So I've been trying to work out this intermittent problem I have been having. Its a 2006 evo on aem v2.

Here is an example of whats going on and how its so intermittent. I can drive the car to work and do a WOT pull and it be smooth. Then on way home from work, my WOT pull will have misfires/breakup. Sometimes its not that bad, sometimes worse. Sometimes I can go 2-3 days with no issues, then it will come back for couple days. It comes and goes randomly. This is all on same gas, boost level, etc...no changes.

Something I have noticed in my logs is that on pulls that go smooth, my AFRs are in the mid 11s. On runs with breakup/misfires, my AFRs are around 12.0 flat; which by no means is horrible, but just something I noticed. The two screen shots i posted of my two logs will show you what I mean. These two logs are same day, same gas, only 4 hours apart.

Also, I am sometimes able to predict if the breakup/misfires will happen before doing a WOT pull by the cars drivability beforehand. Just normal driving the AFRs are different, like slightly leaner, and in between shifts there is a sputter and it goes really lean for split second. When the car drives good though, my WOT will more than likely be clean.

I have tried all the usual things, like new plugs, change gaps, new cam sensor, etc..but nothing has fixed it yet. I am wondering what is causing my AFRs to change so sporadically and my WOT pulls to be leaner than others.