Also see The Boys Tech 2 sight, link at the bottom of one of his posts.
There are numerous causes of a random miss fire, trouble is non are showing a fault code to go with the 0300. Live data shows figures and outputs from engine sensors as the engine runs.
A for instance for you, my car has issues on hot days when starting, just cranks on the starter but wont fire, doesnt happen often for obvious reasons, so its nothing to worry about, but one theory was to check the air temp sensor built into the maf, this is used during the start up procedure as a referance before the maf (Mass Air Flow) sensor kicks in, or something like, the details are not important, but tech 2 shows this info real time.
My car didnt show ANY issues at all under live data, yet the symptoms pursist albeit very rarely. Its not necessary to hit the panic button at every issue or code that appears to point at trouble. If we did that nobody would ever buy a car at all. The Boy has a little mission when ever he tech 2's a car, he can always find "some" issue or other, and usually does. The cars history can almost be read to some extent, in fact his own car throws a gear box code of some sort and is concidered normal i believe. BMW e39 diesels throw a fuel pump code to do with fuel pressure as a matter of course, they run perfectly and you would never know the issue was there.
So i think its wise to take note of the issue as you have, and get it checked at a convenient time to you and your nearest admin with tech2, i guess that would be The Boy? And make the journey with an open mind ready to accept the fact that there may or may not be anything wrong at all. Chiiiiiil Winstaarn.
I suspect some owners would be delighted to only have that code after the pedal trick.
Edit, unless of course new info comes to light, i was writing this as James posted.