06 GT, owned the car about a month and i decided to push it to its limit today. I was in 4th gear just above 5000 rpm and flooring it when I noticed power seemed to be leveling off and then it misfires. It has never done this in normal or even spirited driving and only happened very breifly, as soon as I heard the misfire I let off the gas and it immediately went away.
I plugged in my scanner as soon as I got home and found P0300 for random misfire. Due to it happening only at max load and not specific to one cylinder my first guess is a clogged fuel filter which I will be replacing tomorrow. Fuel trims also seemed to be high indicating a lack of adequate fuel?

Anyone else have ideas if that doesn't do it?

 

Replacing the fuel filter might just work but I suggest you pour a bottle of fuel injector cleaner into your next tank of gas. That random misfire and lean condition could be due to clogged injectors.