04's have the top post batt. terminals.. the 97-03 are side terminals.. the side terminal batteries are notorious for leakage.. I think the engineers thought the side posts would be sealed to corrosion and infact they seem to have quite a bit of problems..
I heard thet even GM gel type batteries were no good. When I was at the dealer a guy came in with his 03' and said his battery was dead after not having started the car in 2 weeks. I was going to go with the GM gel type until I heard that story and then I purchased the Optima Redtop. I love it and even put one in my pickup.:thumbsup:
After I cleaned up my PCM and all the wires under my AC Delco turd, I replaced it with a yellow top. Sleep much better at night knowing that turd is out of my car!! Swap that battery asap! Peace of mind is priceless :cheers: