I think it's been a month that the CEL was on constantly before I finally got to the dealer (discussion/diagnosis over phone w/service tech indicated that clearly NOT the same as issues with the 3.6s)...I had no performance degradation or, really, any issue other than the stupid light. We suspected bad seal on gas cap.

Anyway, turns out that there was a short in the fuel pump wiring, sending a signal that an injector was alternately overpressure or underpressure. Replaced the fuel pump and that was that.

Just another data point.

Butch