To my knowledge these do not store error codes. If the (MIL or EFI in the US) light is flashing, it means there is still an error on one of the related sensors. May only be a connector..but because it seams to be running OK, it might be a contaminated 02 sensor. You can bridge some pins or ground something and have the light flash the error code..which you can then look up on the table. Of just have a shop with the CFM reader plug-in and read it.