Originally Posted by GrayPony
@Nuke.. no COP's on the 4.0...
I was wondering about that as I typed it. My wife has her 4.0 with her at work and I never really took notice before.
I'd still change back to the OE wires just to eliminate that from the list of possibilities. Although it seems like an unlikely coincidence, I'd clean the TB and check to see if the fuel filter has been replaced within the last 30k miles.