The game never stops as those that run around forums and makes claims about what O2 sensors do or do not do and the stupid pitch of needing W I D E band O2s.
One of the other points never looked at is long tube headers like from LG Motorsports that are ill designed and have a total impact on how the O2s report to the PCM and then what levels it adjusts to.
O2 sensors are designed that they MUST have good outside cleaner/cooler reference air. In cases where headers are pushing the fron O2s further back means also they live in cooler exhaust temps.
Add ridding the CATs and rear O2s and the PCM is lied to.
Refer to and study this writeup : O2 scale
Notice the AFR difference as the temp changes.
At the least forcing the exhaust temp to be higher or lower has a neagtive impact and is never considered when adding mods or when tuning the PCM.