i did the paperclip in the obd1 port thing today well actually my coworker did it for me as he custom made a device with multi plugs
anyway i knew my truck was throwing codes but not sure which one
well i had my suspision about it being my 02 sensors well it came up with 13
i used the posting i believe worf posted some time ago
and it is my 02 sensors

it according to the posting says
left bank 02 sensor circuit open or no activity
or
02 sensor circuit open or no activity

so guess what im gonna be getting some shorty headers or some other kind with the 02 sensor wholes pre drilled then new o2 sensors
then it will read no codes