Yes, it's definitely going into open loop during the last bit of the pedal, like it should. I was experimenting with tuning it to different air/fuel ratios, including 14.7 to see if I could get that pulley to work for me. A majority of the time I tried it, I had it on the rich side, around 12 to 12.5 since that's what's in the FAQ at the Split Second web site. But I can't get away from misfires with that pulley.

Yes, I have the Auto Enginuity OBDII reader. I can watch the line graph bounce around 14.7 during typical closed loop driving and the wideband O2 sensor bounces around the same numbers, so I know it's right.

Just to mention it, I've always used premium fuel with the supercharger. At this altitude the highest octane available is 91.

I'll clean the MAF again. It's been a while.

I noticed some others mention concerns about the throttle position sensor on other supercharger posts - that is, that sensor very briefly outputs a voltage of zero in between correct voltages, but the error can only be seen on an oscilloscope. Maybe I should check into that.