1994 f-150 check engine light

bad o2 senser? 202,000 miles

What were your code[s]?Auto Zone will check for you.

autozone says 94 wont hook up to there scanner.have to paper clip under dash.only happens when im pulling big boat up hill and is under powered.wont care but they say o2 sencer adjusts fuel mixture.

To all looking for -how to- on pre 96 codes[non OBD2] go to fordfuelinjection.com