Initially my car was professionally tuned before flashscan became part of me. I know that they used some proprietary software (had to take the chip out and burn it).
At idle I have a commanded AFR of 13.8 to 13.9 and it is in closed loop. Stoich is set at the normal 14.6. So how did they do that? The car idles nice at that mixture. I am in the process of upgrading to a newer operating system so I guess I will loose that feature. I guess I could set the stoich to 13.9 but that would be a little messy.