random lean at idle/ afr wont return after decel

[Ben1315]

having trouble figuring this one out, maybe someone can look over my datalog and see if anything is up. GSR block with b16 head, stock intake mani, 66mm skunk2 throttle body, stock injectors and pump, yonaka 4-1 headers, AEM UEGO, CAI. cold starts and warming up the car runs fine, then it will randomly lean out while driving and come back. When decelerating down to idle, afr will sometimes stay lean, sometimes it will return to 1.00, Just dont really know where to start, just want to see if anything in parameters is wrong or maybe something else is going that anyone can point out, cheers!