When i come to a stop my idle will fluctuate between 800-1400 for about one minute then it will idle at 850 like its suppost to. I also just put a wideband in my car and everytime i let off the gas it spikes lean for a second then it goes back to being fine wtf could cause this? The car is a eg hatch with ls motor and has skunk2 manifold. also no cel's or mil's