If your car has an up graded ecu, subaru would not be able to Read anything with it's computer but the lads will fill you in more on that one. If it has not been done most here would recommend that you sort that asap.
You could pull back the carpet on the Passenger side of the car and open the ECU housing that will let you Know if it was done also as it could be a None subaru ECU eg. Apexi if it is then It more then lightly was re-mapped.
Thanks Lads, Will try have a look at the ECU in a while, must look into the Lucas stuff too if not remapped, or is it advisable to use octane booster even when remapped?