Just a quick post to let you know (some of you may already have this) if you download an iPhone app called:
in the top right hand corner there is a button that says:
As you know error codes on engines are pratically standard across car makes i.e. the same error code on say an astra will mean the same problem on a focus.
So you can do the pedal test, note the code it gives you, fire up the application and entre it and it will say something like:
0170 is your code this means 'Fuel Trim Malfunction (Bank1)' <----- taken straight from the app
Not sure if you can get this on Andorid (if you can't tough ) but you can get it on the iPhone/iPod/iPad!!!