Fault code reading on a K11 2001

[N1554N]

this isn't a how to (sorry) is a How???!!
i have a K11 2001 micra S. the engine management light is on. i recentlt replaced the MAF sensor (but didnt reset the light straigt away).
this weekend i reset the light, but a days driving and its back on!
i went to get a fault code reading using a guide on the net (the paperclip method), but nothing happened.
this is the socket thats near my fuse box: (the one on the left)

 

[frank]

you,re best to use a codereader on the obd2 ones
probs 0171

 

[N1554N]

thought as much. is there a recommended reader, or do they all pretty much do the job? (i'm talking about an ebay jobby here)
although i've been quoted £35inc VAT to have it read by a garage and these readers cost about £25....