On reflashed ECU the O2 sensors are disabled (too lean with).
There is a barometric sensor, but only one...
One measurement is done before starting, because the same sensor after measure the vaccum to estimat mass air flow !
When changing altitude, it is preferable to switch the engine off and on again, so that it can be taken into account...
page 19 and following
https://1drv.ms/b/s!AuqxioVGI9b-hvg5SvgEa5IpTHf2_g?e=QidGkH