Excellent, thanks guys for the fast response. From what has been said and the checks I have done I have narrowed it down to:
-Inlet air leak
-Maf sensor
-Faulty O2 sensor
How do you check the amplitude and frequency of the O2 sensor? and what should these values be?
Also how do you check the MAF sensor?

Since I have reset the code I have driven 100 or so miles and it hasn't come back, but I'm not holding my breath. Is it possible that it could just have been a glitch, do these faults occasionally just come up for no apparent reason?