V6 12valve question

[Gaidos, A.]

All, on behalf of my Canadian friend I'm asking this question. The car is a
90q with the v6 12valve motor. He is getting a check engine light and the
fault code is saying it's the oxegen sensor. His Mechanic gave him a quote
of $1500 total with $1200 in labor to replace the sensor. This seems a
little extreme. The mechanic tells him there is some serious R&R to get to
the sensor. Anyone have any information on this?
Thanks
Anton