Just got the error message above tonight,

from reading through the forum it seems its either a bag or a tank, is there any easy way of telling, and are they easy to refill? (The engibe fault appeared at the same time so presume its that)
I also think the ECU needs resetting using Diagbox, would a snapon diagnostic kit do this or only Diagbox does anyone know? I have access to a Snapon one, but would have to buy Diagbox/Lexia. I was thinking of doing that anyway as I think one of the injectors is on its way out, are the kits from Ebay ok to use? I looked at EasyDiagnostics but they aren't selling cables at the moment, and the software isn't much use without one

As the warning has just came on, I presume it will be ok to use for now, especially as I'm only doing about 50 miles a week?
How good will Diagbox be for diagnosing the injector problem? Is it easy enough to use? Or is there anyone local to me who has it and could diagnose the problem (and reset the additive counter at the same time)?
Thanks in advance for any help
Also, for admin, when I was registering I got an error saying 'the entered email domain has no valid MX record', thats from a 20 year old domain and had to switch to using a hotmail account.