I got this truck and the p/o removed the o2 sensor and cat and ran it in open-loop i imagine. The cover on the AFM has been removed and i assume the adjustment screw tinkered with to get it to run only moderately rich? I'm trying to un-f&&k this thing back to stock. Any one have some basic info on how to revert all this when i weld in a new O2 and hook it up again? Or should i just buy a replacement.

Pic for reference: https://i.imgur.com/5o8K3JM.jpg