I've had the same issue with both of our Tributes. Cleaning the Throttle Body is a must. I recommend removing the body, spend some time with it and clean very well, especially at the butterfly. Have new gaskets on hand for installation. Don't skip this, if the old seals have failed it can cause problems. Next, Replace the IAC valve. This is located on top of the engine held on with 2 bolts.(chrome color) If it has never been changed then now is the time. (I've tried cleaning them, but that has never worked for me) They are easy to do and not that expensive. About $35.00. (In fact, do this first and see what happens, it may be the fix you need) Then, Clean the MAF sensor elements using MAF cleaner. The sensor is located in the air intake manifold just after the air cleaner. Do not remove the sensor itself but the housing and spray the cleaner over the sensor element. Also, run a tank full of techron 3 or 4 times a year it will help keep the system clean. Remember to only run Regular (87) gas. These cars do not like the higher octane, Also, do not add octane booster. Do a scan of the PCM and be sure there are no hidden error codes. At 100,00 miles I would replace the manifold seals and all the coil packs but that's just me. I did that on our 2003 and that one is full of Zoom. My 2004 has new packs and seals also full of zoom. However, The rear seals are a tough job, the fronts not too bad. The coil packs are not hard to change. Shop the net for best prices. I did a set of 6 for under $100.00 about 1 year ago. Good Luck!