Misfires mean that you're not getting enough of the four things: spark, fuel, air, and/or compression. We've got a great write-up on the code.
That'* the good news. The bad news is that you need to check pretty much every major component.
If you have an O2 sensor code, make sure it'* plugged in; if it is, then replace it. (That'* the next step on the write-up anyway.) If it'* got over 60,000 miles, it'* probably best to replace it anyway.
The only times I had my engine misfire (randomly, not one cylinder like yours) was a few years ago when coolant was filling the cylinders (UIM failure), and again last week when I redlined it with the needle on E.
Good luck! Keep us informed.