You could try to disconnect the battery and leave it disconnected for a few minutes, 20 should do it, then reconnect it. It should reset the check engine light. But make sure you have your porsche radio code so you don't loose you pre-set stations. If the light stays on you may have to have the dealership clear it, or go to your local Autozone. Autozone uses an O.B.D.(on-board diagnostic) tool that can be used to clear the code.