360 Magnum with stock EFI engine codes

If I remember correctly the donor truck only had one pre cat O2 and it was just past where the two exhaust pipes came together. Maybe I’m wrong
Could be, Ive seen stranger things. And I know with emissions stuff the manufacturers make different configurations for different states. Mine for sure had 2 pre and 2 post cat o2s. Mine is a 2001 ob2 California truck.