Hopes this helps someone else. Replaced plug wires--no fix. Replaced ignition coils--engine now purs like a kitten. Here's a question for those more knowledgable than I. Can bad plug connectors, and or plug wires lead to premature failure of the ignition coils. (I think I may have read something about this somewhere on this board) The reason I ask is that the iginiton coils I replaced had about 50k miles on them. The car has 178k miles. The plug connectors and wires were original