Strange running habits, need help.

[texas tough]

CMON GUYS!!! hes getting a freakin code the second it acts up..
Pull the codes with a metal paperclip,, top right , A and B terminals..on DLC connectorv u will get a 12 then something else then 12.. tell us the something else number,,,

 

[Macg]

Sounds like O2 sensor bad. Without the reading computer has to "guess" thus the up and down.

 

[24 Karat Brown]

Sounds like O2 sensor bad. Without the reading computer has to "guess" thus the up and down.

Seems like just about everyone is connecting this to an exhaust issue