Well I posted over at msefi.com, and someone had mentioned that the overboost protection was kicking in the hard cut limiter. I checked that setting, and it was at 14.7 psi, which comes standard in the code. So I changed that to 21 psi, but i cant take the car out since its raining now. I'm wondering if that was the cause of the big backfire, as the ignition may be dropping spark from the hard cut limiter. Then all that unburnt fuel is igniting in the exhaust. The Mitsu ignitor stays super cool at idle, which is why i think we can up the dwell more. Hell, that module is mounted to the cylinder head on the 4g63, which gets pretty damn hot! I think that module should be pretty robust as far as heat is concerned. We really need to see what the stock ECU is doing with the igniton trigger signals though, on the scope. That would really solve the dwell issue. Nate, do you have any idea what the discharge period is supposed to be set to? I'm assuming that this is the time for a complete discharge of the coil after spark fires, but I wonder what it *should* be set to. That setting may def be having an effect.