CEL frenzy, after driving through standing water

New to SubaruOutback.org. I have 2010 Outback 3.6 and 2017 Legacy 3.6. Outback is my swiss army knife and has weathered blizzards, hurricanes and nor-easters without a single issue till now.

Reading forum about Engine, Cruise, Brake Christmas Tree effect on forum. I had to run through a 4-5" of standing LI Sound water with Outback today after NorEaster and started getting the Christmas tree light effect. AGM Battery 1 mo old and gas cap tight so those are not issues. Car was running rough after passing through water and the idiot lights came on. Checked air box and battery cables and everything is fine. Car has since "dried out" and engine seems to be running fine.

Has anyone had similar issues after running through standing water? Unfortunately, passing thru standing water from storms is getting to be a regular fact of life where I live on Long Island and won't be able to avoid it. That is reason why I have Outback and leave wife's Legacy in driveway under such conditions. Just as precaution I will go to Autozone for computer check. I hope its not O2 sensors...