Goes limp mode in rain

[Jamest0809]

95 k1500 210k miles, 350/ rebuilt 4l60 10k ago
When I drive through a puddle or in the rain for awhile the truck bogs down and basically goes into like limp mode, and doesn’t want to accelerate at all, if you stop and put it in park it revs up and sounds fine, seems like maybe a electrical issue with the transmission maybe? Any advice at what too look at?

 

[Schurkey]

Bare wires at knock sensor, O2 sensor(s), or any other sensor connector/wire harness that could be damaged and no longer weather-sealed.

Potentially ignition issue--either the parts directly or the wire harness.

 

[Macs Garage]

I had an 02 sensor wire touching the front driveshaft causing a small hole in the insulation. Caused problems every time in rained.