I often wonder why someone would read out OBDII diagnostic codes and then simply clear them without writing them down and finding out what they are trying to tell you about the car.
11 codes sounds like serious problems so you might want to find out what those problems are. If the car still runs smoothly you can drive it until the error codes return, read them out and write them down. No reason to erase them until the problems are solved. If the car runs poorly, have it flat-bedded to a good local Porsche indy mechanic for a thorough diagnosis.
Also... these cars hate being run out of gas and it screws up their DME fuel trim programming so avoid driving it below 1/4 tank.