My perfect ride is having probs. I only have 5000 miles experience with this vehicle. Recent and sudden onset of rougher than normal idle and sputtering hesitation at around 2000-3000 rpm. I have been going through this a little at a time, and one item I have yet to replace is distributor cap and rotor, which has been recommended. Could this be culprit, or at least, best place to start? Other ideas?? Thanks.