Ive been searching the Hp Tuners forum and cannot find much info on this. I am tuning my 3800sc with HP Tuners and I have calibrated my MAF and adjusted my AFR to where I want it. But now I am having issues while shifting at WOT. Manual Trans. When I let off the gas to shift it dips rich, then I get back on the gas and I get a lean spike which causes KR. Has anyone else run into this? Is there a way to get rid of those lean spikes. I would assume the spike is caused by air rushing past the MAF to fill and pressurize the supercharger and intake but it has not gotten into the cylinders yet.

Turned out to be a boost/vac leak at the oil filler cap. I found it by pressurizing the entire engine from the throttle body with a round plate and air fitting I made. Turns out to be one of the most useful tools I have. I make them for all the boosted cars Ive had and they make it a lot easier to find leaks than the spraying carb cleaner method. Got it fixed.