i would try to find someone with a wideband and check fueling with the mines and 1bar of boost before you get rid of the ECU!!!
Change valve steam seals while you are there and check the valve guides for exessive play by lifting the valve to the normal working lift and by attaching a micrometer indicator to the valve. Then move the valve and compare the indicator readings with the 5e service manual.bump wht do uthink about stem valves ?? ^^^^^^