Had a large amount of rainfall in a short amount of time last weekend in my region of the country which unfortunately caused some streets in my neighborhood to flood that have never before flooded. Drove the car through water which was not any higher than any water I've driven my previous Honda Accords through...anyway, drove the car through the 10 or so inches of water and it came out fine. Next morning l took it to the mechanic near my house just to have an oil change to make sure any water in the oil pan did not circulate through the system. Now l have two problems: the airbag light has come on (which l know l will have to take to Lexus/Toyota to have them hook up to the comp. system and diagnose for me) but more importantly yesterday when l got in the car to start it IT WOULDN'T START!!!!!!!!!! l finally got it started by holding they key in start and pressing on the gas to rev up the engine but it would idle down and shut off as soon as l took my foot off the gas. Anyway, after l sat there with my foot on the gas for probably 60 seconds it stayed idled enough for me to put it into drive and get it charged back up again. l think this is related to the exposure to water and wondering what it could be, is it repairable, or am l going to have to contact my insurance company and hope that they just total out the car to avoid future problems. HELP!

Might have gotten water inside your ISC motor (Idle speed control) and possibly corroded the slide inside. l suggest taking the throttle body off and cleaning the ISC and throttle body with some carb cleaner.
As for the airbag light it could be multiple things but very possible its the drivers seat wire has a poor connection (common problem)