I have a '91 Accord 4cyl with about 125 grand on the odometer.
My car was recently flooded with water from a heavy thunderstorm. It's an automatic. Twice I've flushed the tranny fluid, but it's still slipping, and doesn't have the kick it used to when I accelerate. It picks up speed gradually instead of that nice kick into gear I used to get, especially when needing speed and merging onto the highway. Also, when I start driving, the engine light goes on and stays on.
Get the engine codes and we can start there. Just draining the oil from the tranny is not enough. There is fluid in the tranny, lines, and radiator. You would need to drain them all to get the system clear of impurities.