To answer your question in your e-mail... It's open loop at WOT, but techincally it's referred to as power enrichment (PE) mode. ECM ignores the O2 sensor in open loop and you pre-program what AFR you want in this mode (as well as in cold start mode). You can control when PE occurs based on coolant temp, MAP, and TPS. Factory is pretty conservative about it (no PE until pedal-to-the-metal) and then AFR shoots down to 11.5:1 (way too rich for max power). On mine, I have it coming in at about 60% throttle and AFR set to about 13.0:1. We can work this later after we establish a good normal operational baseline. EDIT: BTW, your chip guy didn't even touch your PE tables. They're bone stock. My hunch is you have a significant amount of torque to be gained later by tweaking these tables (I picked up a bunch going from 12:1 to 13:1).