When this tread was started there was no NGK option either. NGK only offered a replacement very recently. it's so recent that the parts stores don't even have them yet. Most of this thread has been about what to use in the absence of Denso and NGK options.
When I had the misfire issue it was intermittent. It ran normally almost all the time but occasionally would misfire. When the missfire happened, rasing the rpms a bit would clear it up. Assuming the car is under warranty, take it to the dealer. They'll replace the coils under warranty with that misfire code.