Pulled caps and rotors and they look ok; no green build-up or residue. That portion of the ignition system was replaced approx: 8 months/15k miles ago.
From what I've researched about a failed ETA is that they either work or they don't. (There isn't an "in between" where they'll cause slight problems)

One additional "fishy" thing that I tried to get feedback on in an earlier post is the arching between the spark plug and the plug wall when sprayed with water. Anyone have any insight into this method of testing ignition components?

Keep me posted...