I finally found the source my random miss code problem. If anybody remembers, it occoured when the AC was on at idle and I was about ready to blame it on the compressor. Turns out it was the harmonic balancer coming apart. It finally got bad enough that I realized what was going on and everything is much smoother now. I don't like the design, particularly, but there isn't anything that can be done about it unless there are aftermarket types made differently. The rubber is between the outside and inside of the pully and takes the full force of whatever is loading the serpentine belt. From the dealer the part is about $250 but Autozone has an aftermarket that sells for $66 and seems ok.