I am tuning my stock 2005 expedition using HP Tuners amd WEGO 4 widband sensor. The datalogging shows that the it running too lean at WOT 14.3-14-8, and the timing is retarded to 3* total timing. I know that is very dangerous on the engine. Is this A/F ratio normal for the expeditions from the factory for emission and mpg purposes? Or I am having a mechanical problem causing lean AFR? I have checked the fuel base table and its comanding 0.82 lambda in the WOT area. Can anyone advice me. I have tuned some mustangs and they were a little rich for engine safety 0.82 lambda for 14.6 Stoich afr. Also, there is no DTC detected.