Wow that is really weird. Interesting problem though. I don't think it would be an O2 sensor though becuase the O2 sensor doesn't determine if it is in closed loop or open loop. Usually that is determined by the temp of the engine. So my question is what is the trigger for that the VSS sensor the TPS sensor or some combination of information? Your accord should have a separate computer for the transmission? If so maybe find out what sensors it uses for input and do a check of those sensors. Don't know but let us know what it is if you figure it out.