2004 Sonata slows down in the rain

[kargirl38]

New to this post, but lately my 2004 Sonata's transmission gets stuck when I drive in heavy rain. The engine light comes on for a split second, then the RPM gets stuck around 3,000 and it wont get out of first gear and it slows down to a crawl . We were going up a long hill the other day (in the rain) and pulled over because the car just didn't want to do it. Also then noticed a smell from under the hood but no smoke. IT happens daily as it has been raining every day here (east coast pittsburgh). After the car sits and dries its fine again until it rains. If it was a trans problem wouldn't this happen even in dry conditions?
I had the trans fluid changed at 52,000 miles . When I bought it it had 22,000 miles on it . Now its coming up on 75,000 should I get it changed again. Just had the oil changed about 2 months ago and they didn't see anything in the transmission fluid. Someone also recommended replacing the air filter which I will try first. The car runs fine when its dry out, no problems what so ever...Going to buy an air filter after work and see if I can install it myself.
Also i keep going through front head lights like crazy! Just replaced both bulbs AGAIN after about 4 months of replacing them before. First the right one goes out then the left.

I would be most grateful for any advice on this one.

[Bear]

Fluid and filter every 30,000 miles is a good idea and be sure and use ATF+4 as Dexron or Mercon are not what this transmission uses.

[kargirl38]

I stopped at a local auto parts store, since the engine light came on they did code test and said it was a wire that is tripping and suggested that I change the wire and sparks. I changed the air filter and oil was changed just last month also. Total cost of repair 56.00.
Will be getting transmission fluid changed very soon as well.

[r1bourg]

I washed down my 2004 Sonata 6 cylinder engine last week to remove road salt from winter driving. The car stalled and limped along for a couple minutes. I attribute this to getting water on the serpentine belt(fan belt) and wiring. The wet belt was likely slipping a bit. Water got on the spark plug wires and may have been shorting? This might be similar to what would happen in a rain storm.