Missfire after drag racing, common?

[Twilightoptics]

So I finally took my stock 7 to the track (removed emissions and cat) and upon completing 9 passes on the way home and at idle I notice a light miss every so often.

Idle and cruise was rock solid before. Doesn't seem to hickup under acceleration.

Is this common? I've got only 4000-5000 miles on a fresh tune up with the middle NGK plugs.

I thought she was stronger too! Only mustered a 17.25 @ 79.20MPH in 80º weather.

Thanks for any input.