UPDATE: My car has been running well since wverything went back together. Not sure if it was the numerous reseating of the ECU or the resealing of upper valve covers. Having broken a couple of the aluminum screws for the valve covers, I was wondering what the size of these are. I think I am getting a slow vacuum/pressure leak, and need to replace these with reliable bolts. If my car seats for a couple of days then it has a slight stutter when I fire it up. Once the car is warmed up and pressure is back to normal then it drives fine. I may be diagnosing wrong, and will see how the plugs look when I change them this weekend; so if anyone has any info, advice, and the size of the upper valve cover bolts, all would be greatly appreciated. THANKS