Hi, we have an Audi S5, we randomly got a misfire 2 weeks ago, have changed the plugs and the packs, it's still there, so we started looking at sensors as we have code G247, but could it be a leaky injector instead.

Welcome Clare and thanks for joining.

It’s great that you are DIYing this, and if it were mine, I would be ‘investing’ in a pressure sensor to hopefully sort 247, before moving on to other more complex possibilities.  Worth buying a quality brand such as Bosch rather than cheapest available. 
Perhaps you could keep us posted on developments. 
Kind regards,

Gareth. 

Could it possibly be an injector? Whilst the supercharger is off, is it worth getting them flow tested incase, as the sensor says its malfunctioned not an open circuit.

Sounds like you are rather set on going down the injector route then Clare. 
My logic comes from the school of eliminating the least costly things first, and that has always stood me in good stead. 
Yes, you can claim the sensor is fine since it doesn’t test open circuit, but is that an acid test under constant operating conditions? 
Yes, possible injector/s issue; yes, could be fuel pump issues, but I know where I would  want to start my elimination process from. 
Kind regards,

Gareth. 

So after sending the injectors off, it has come back with number 6 is dead, and the rest cleaned and flow tested. Does anyone know what parameters they should be within?