o2 sensor replacement recommendations?

[dirty4v]

trucks got 150k on origional o2 sensor, should i replace it? no running complaints to justify replacement, but i've read at 100k they should be replaced. also, where is the spout connector (ford guy here) so i can check and adjust timing?

[corax]

What year truck? if it's newer than '96, and there are no codes stored or check engine light isn't on, I wouldn't worry about it.

[dirty4v]

it's a '94 model