I must be missing something here. When I use the TTS auto-tune feature I am calibrating my front/rear V/E tables in my ECM Map. As I understand it, these values are used by the ECM to calculate the injector pulses to produce the requested AFRs in the AFR table. So far so good. But most maps show 14.6 AFR throughout the normal riding range. And a value of 14.6 means the ECM runs in closed loop mode. Doesn't closed loop mode mean the ECM is using the O2 sensors to measure the actual AFR so it can adjust the injector pulses to hit the 14.6 ratios? In this mode, the V/E table entries are ignored, right? So if I spend most of my riding in closed loop, why was it so important to calibrate my V/E tables. Like I said, I must be missing something.

 

the V/E table entries are ignored, right

Heck no,
The VTune is working to change the VEs so that a selected 14.6 is an actual 14.6 and not some other higher or lower value. Consider the VE as a factor in a complex equation. After the VEs are fixed you can dial any part of the AFR curve where you want and with relative certainty know that the actual AFR will be close to the desired, assuming the tune was done properly.

 

The "spend most of the time in closed loop" portion is debatable.

Personally, I don't think we are in closed loop near as often as some are inclined to believe.