i don't know if anyone has noticed, but it seems like there have been a lot of questions about engines running rich or lean lately on stangnet. So i was thinking about EFI and all the sensors and whatnot. My question is this...at wide open throttle, i know that the engine goes into "open loop." What exactly is "open loop" ? Also, I think the engine stops getting readings from the O2 sensors to measure the air/fuel ratio. Instead it gets its reading from the MAF and adjusts the fuel accordingly, right? Is this what every EFI system does? or just our mustangs?