There is a recall and service notice for this problem. I took mine (2004 4wd club cab) back to the dealer and still had the problem. I pulled the heat shield off behind the right bank catalytic converter and noticed they (dealer mechanic) had only squirted silicon down from the top of the heat shield and it wasn't even close to the ac drain. I'd suggest fixing it yourself if you want it done rignt, or insist that they remove the heat shield and do the repair corectly. I siliconed around mine and punched a hole in a 2.5" innertube patch and stretched the patch over the tube while the silicone was still tacky and the problem was gone. I used a piece of steel pipe and hammered the hole through the innertube patch. The hole was smaller than the ac drain tube and the patch is larger than the hole through the firewall. I had about 2 gallons of water in my floorboard before I discovered the problem.