I'd be expecting to see the lower end of that scale for an OEM tune, but certainly not in the 11s.
Ok. So there is some doubt about the accuracy of the data (although the reading at idle looks about right). Is there any way a standard garage (without all the fancy tuning gear) could check this for me?
If the mixture genuinely is rich, what could be the reason?
Could this be a symptom of restricted airflow, for example, a blocked filter?
Would it be worth me replacing my standard paper filter with a high flow K&N, for example?
Has anyone else had this measurement done on their car? Do the data look similar?