have you scanned the o2 sensor yet? wot it should be hitting 930 ish (mv) and stay there. if its drops that can cause kr. i had one drop to 0.78. chased my tail for a bit on that one.
I havent.
Until i did mods, i figured the 3* stock was pretty normal so I didnt pursue it at all.
I did do a pull before the car hit 180* at about 150, i had 0 KR.