Hi Ian yes, if there is an air leak, then yes adaption cannot be performed for some reason. (even though its done with ign on ONLY, and does not make sense, but there are things on cars that that we will never know about and seem odd, but accept it when we get the botton of it.)
And i have just re-read the 1st post again which highlights this as his 2nd block is -93, which indicates a leak at high engine revs.