Table B3649 is a semi-open loop table that uses the O2 sensors to update the AFR only WHEN 14.63 AFR is inputted into the table. If you put any other value into the table it indicates that the PCM will be in full open loop operation with no O2 feedback and no STFT control. So, if this table commands say 13.5 AFR, where is the feedback coming from? Does it use the VE table- if so, why use table B3649 at all? Why do you need to set STFT idle to disable in table B4108 don't we want STFT correction?