Gear Shift sticking
 

My car was recently looked at and everything was fine with the car until last Thursday. We had severe flooding in our area and the only road open to get home did have puddles but nothing so bad it would be deemed impassable. Since then my gear shift has been sticking. It is very hard to switch from Park to drive and vice versa. When I do put the car in park it stays parked but the car won't turn on because the car doesnt seem to be in park. The same thing happened when I put it into drive it stayed in neutral. My check engine light is also on, I am having the code pulled tonight. Any ideas on what this could be?? Please help!