I have posted a couple messages this week about an idle stumble, and hesitation under hard acceleration. The previous owner had the car to the dealer several times for this problem, the dealer replaced the DME, the ICV, the battery, and reported that they could not verify the problem in a few instances. Yesterday I did a tune up - new plugs, cap, rotor, air filter, and valve adjust. Every valve was tight - tighter than the bottom spec. I adjusted them all to 14, and after the tune up, I am happy to report that the problems are cured. I also noted that cylinders one through 5 had platinum plus 4's, cylinder 6 had a standard plug. Wonder if I should call the dealer and let them know?
It does make one wonder what kind of process has someone replace expensive parts like DME and ICV before checking some basics?