2008 Porsche Cayenne gts

Sell my Porsche Cayenne gts v8 4.5 liters Yellow motor light from time to time so sporadically it goes on and off sometimes he does not start the second time the first time and the second time immediately do not know what the car has age-appropriate wear traces is also not the newest vehicle otherwise it drives without problems and switches also clean checkbook was lost but so that I have only 2-3 pictures of it otherwise as said car runs and drives every day with it to the yellow light where goes on and off and when starting from time to time he starts up according to a colleague it should be on the lambasonde that the yellow light on and off but sure I do not know it just write for further questions