The war diaries of the 86th FG are all online here:
http://www.86fighterbombergroup.com/War%20diary.htm
They were based on Corsica on Sept 8th (getting ready for a move to Italy). On September 8th the weather was bad and they did not fly any missions.
The 324th FG (see history here):
https://www.armyaircorpsmuseum.org/3...hter_Group.cfm
had just moved to Amberieu, France on 6 Sep 1944. Amberieu is just to the NE of Lyon, so not too far away.