[mwebb]

yes bank 1 and bank 2 are independant
they share a common load sensor and fuel supply
but fuel trim correction per bank is unique to the bank

the system will trim on the rear 02 sensors as well

if both banks have long term fuel trim corrections that exceed +/- 10% and are the same
the problem is in load calculation or fuel supply or air supply

if only one bank has such an error , the problem only affects that bank

Originally Posted by mechman600

Quick question:
Generally speaking, on a V6 with 2 upstream and 2 downstream O2 sensors, does the PCM adjust the AFR of each bank independently based on values from their respective upstream 02 sensor, or does the PCM adjust the AFR of both banks together with combined values of the two upstream O2 sensors?
Curious is all.