Ya I'm betting the sea foam didn't do anything. If its your valves (which helped me some but not the ever known mysterious start up idle stumble, and not the WOT 3rd gear misfires) then you'll need to do a real walnut cleaning. Seafoam has been shown not to have an effect on our valves if they are too far gone.

I checked my plugs and they were all gapped right. I'm leaning towards the cylinder 1 injector.

 

Mine is doing the same exact thing! I couldn't figure it out. I even took it to my brothers shop and he said everything looked fine. Fuel pump, coil packs, plugs, and wiring were all perfect. However I bought the car with 83,000 miles and don't know if there is a tune from the previous owner. What upgrades do you have on the car?

 

24 psi e47 trifecta tune, intake, exhaust

 

You were right......The dealership installed Autolite platnum plugs with the wrong gap. I bought ACDelco's and checked gap they came out of the box at 32 gap as Ive seen stated on here. Installed them and no more misfire been driving for over a week now with multiple WOT pulls.