A friend of mine had this problem and he put some barrs stop leak in to stop the water from getting in he just did this a few weeks ago but has worked so far

Hey guys... I unplugged the battery cable, left it uplugged overnight (instead of for just a few minutes, like I tried before).  The light is off this morning and stayed off the whole way to work (albeit not that far).  We'll see how it goes when I start it up to take it home.

Here's hopin fer da best!!

The problem with the battery disconect is a bit sticky.

Yes it will clear the codes.  It will also clear ALL of the computer memories, including the system monitors.  Each monitor is a series of test.  Each test must be in order, and each monitor must be in order.  When all are complete, it can do any of the test at any time conditions are met to perform the test.  They do not need to be done in order at that time.

If the problem is corrected without clearing the memeory, the system will retest the problem.  If it passes in two consecutive trips the light will go out and all systems will pass.

If the memories are gone, the light will stay out until such time as the computer repeats ALL of the monitors before that test is run.  Depending on driving conditions/habits, this could take a few day to a few months.   At that time when it does repeat the test in sequence with the others, the light will come back on.

If all the monitors are not passed, the car will fail an emission check.  It does not have to have the light on, just not passed the monitors.  This also does not mean failed, but can mean just not done yet, or could be failed.

It is often more efficient to repair the car and let it do it's own retest and shut off the light.