i think your maf sensor must be at fault mate, as for wether the code-reader is to blame, who knows...! maybe avoid using it again just incase. (perhaps a short circuit within the code reader has back-fed a current into the ecu, potentially frazzling it!)
do a bit of research online and youll find how to test your maf sensor, you'll be looking for approx 1 volt between 2 of the wires, which should go upto nearly 5 volts when the throttle is blipped! then there should be something like a 12 volt supply voltage to another wire and then one more wire should be direct to earth!
dont take my word for this, my memory of it is a bit sketchy, but you should be able to find it online somewhere!

Hope that helps!

if it checks out as it should then maybe the code-reader has done the dirty on the ecu, but hopefully not.