Did the tune-up a couple of months ago. The car is the wife's car and she works at the local ford dealership. She told them to throw all the parts at it they could, but they only did the plug wires since the platinum plugs were still as good as new. I don't know if they did the fuel filter or not, but I put one on it about a year ago. I'm kinda wondering if the IAC could be acting up? As far as I can tell, it hasn't been changed. Up until I did the tune-up, it even had the factory plug wires on it, so I kinda doubt it. Acording to the rap sheet the dealer has on it, all it has had is a battery, tires and oil changes since the day it was new. One nice thing about this car is that it was a local one-owner that was bought new from the dealership she works at, and the owner was very insistent that they were the ONLY ones to pop the hood on it... even for oil changes and tire rotations, so all of it's service history is on file.