where is mass airflow sensor located, if possible with picture on 1991 Chevrolet Lumina

a friend used diagnostic computer and the diagnois was mass airflow sensor,not a mechnaic,have book need more location information

Asked by for the 1991 Chevrolet Lumina
i owned a '91 lumina with a 3.1 for 7 years and as far as i know there isn't one on it.. although there is a small air flow sensor in the air intake tube.