Changing a Cam. I disagree, altering the tables to bring the mixtures back into line again is far easier than starting fresh on a new After market ecu. As for putting the ford ECU onto another engine as a holden. Then yes, I agree, Aftermarket ecu will be heaps quicker to tune. But you wouldnt get no were near the same quality of tune. Manufactorers spend thousands of hours fine tuning things like cold starts etc. As Dave said, even after spending plenty of time on BCL's motec tuning, they still had problems. Stalling etc. At the end of the day, I dont know why any tuner would take it upon himself to Fully tune a aftermarket ecu onto the ford when there is a editable computer sitting there saying Please, tune me.. Dynowog, The ford does not use Guestimations or Oxy sensors for fuel control. If you open your CAPA/SCT training manual, you will see the big formula on page 73 used for the fuel control.. Unless you fell asleep during the course @ Amberley's last September(I saw many get some Shutteye during the course, Where you one of them??), either way you should understand it quite well.. Using the table names in the SCT software, it looks like this MAP - (map_at_zero_aircharge * Y_Intercept_Corr_of_Map_vrs_Aircharge) * ((560/(act+460)) * voleff_corr_for_ECT&ACT) ---------------------------------------------------------------- slope_of_MAP_vrs_aircharge * (1 + egr_flow /100)