What is interesting is that the way the cap is constructed the number 4 terminal actually passes right next to the number 2 terminal internally. I did read about moisture and it said to insulate the AC line that passes by the distributor. I still find it odd that it always number 2 and 4. If it was from moisture and carbon tracking I wouldn't think it would always be the same cylinder. It does have AC platinums in it. I may try a cap from the dealer next time. I put an Echlin from Napa on this time. It is the original coil on the truck. It is running fine now. I got my kids car fixed so he can drive it and now I am on to pulling the transmission out of the 03 to see what broke. It is a lot funner to work on cars when it is something you want to do instead of have to.