I just got my 2002 A4 Quattro today...the CEL is on and it is the codes for both O2 Sensors(both banks) and was told this is usually a mass air flow sensor, also warm starts take 5-8 seconds of cranking( about the time i would give up it starts) do these issues sound related? once running it runs great, doesn't seem to be running rich or anything from what i can tell