No, PV won't affect idle AFR. Mark Whitner did a you tube video to show how it works. If you google Mark Whitner power valve idle test or similar you can find the video.
Also, I agree with mderoy. I'd trim down the MAB back down. Why did you open the MAB up that much? I also forgot to ask if you are using T slot resticters. You may be better off restricting the T slot and using the the smaller MAB.
