I live in Johannesburg, South Africa, which is 1600m above sea level. I wonder if anybody can help me with a few issues.

Firstly, there is a lot less oxygen in the air at this altitude. When calibrating the WB02 a AFR of 20.6 would therefore not be correct? How can one calculate the correct AFR for calibration at altitude?

Then on tuning, vemsTune has a barometric correction setting. I have set baroCorr to Enable, dBaro to 30 and airden_ignore to 80, but in my logs it shows gBaro as 100? The normal air pressure at this altitude is around 85kPa?