This related to a Camaro that had Head/CAM mods where unknown to owner the shop that did the work shitcanned the stock PCV system and in effect fouled up proper venting of oil fumes causing front O2s to report a large imbalance.

In reviewing the scanner recordings the owner sent me which I analyzed and reported to owner that some problem existed and suggested they check out the PCV system where they found the PCV system was hacked up and the left head was found a hose hanging down with a small filter.

Owner had a stock PCV system installed and we find all the ills of what O2 sensor reported gone and now they report correctly and equal for both heads.

Closely look at the O2 values for PE and WOT, Top results is with the crappy hacked PCV and results below is with proper stock PCV system installed.

When a OBD scanner is pointing to a problem, believe it and do whatever to find out the cause and correct.