Can't figure it out

[Mario Hernandez]

I have a 2003 Sierra 1500 2WD.

Every time we have a heavy rain the truck will start bucking and cutting out while driving, then it will not start for awhile afterwards.
I have been under the truck with a spray bottle hitting everything electrical possible, but not getting the same results.
Also when I take it to the dealership, it gives codes for parts that have already been replaced, they also replaced the computer with the same results.
Anybody have any ideas?

 

[98trck]

wheel speed sensors
will cause engine to reduce power at times and possible brake cycling
this sounds like it would cause bucking and cutting out