I've made dozens of test runs and measurements on my 1150 with test instruments attached you can see many of them in this long thread, Motronic with Wideband O2 Sensor
. One of the tests I made while Open Loop shows the improved mixture obtained by adding an IAT reducer (see graph below). It really shifted the Air Temperature seen by the Motronic and that did richen the mixture. However, after I reattached the O2 sensor, even measuring the Open Loop transients (acceleration enrichment) I could not measure any difference after I rode the bike for a couple hours (see the second graphs in the link).
So my question is, what test could I devise or what measurement could I make that would show an effect after I'd ridden with the O2 sensor connected. Any thoughts?