i`m just bumping this back up, maybe someone else will catch the issue. wording your post titles is key to getting answers alot of times. if you cant find the problem, maybe post "2005 mustang V6 problem with o2 sensor" or something to that effect.
alot of times when someone has a problem with the o2`s its from doing some other repair, crossing some wires or pinching a wire?
05 V6 auto,
"The V6inator" torch red, base, amustangrocksleather padded leather armrest, shift boot and e-brake cover