What do you think would be adjusted for catalyst degradation? Your AFR, that's what. Fuel injection, combustion efficiency and catalyst efficiency all play a role on the AFR. Your ECU is trying to meet EPA standards so when combustion efficiency(albeit almost negligible) and/or catalyst efficiency degrade the only tool your ECU has is fuel correction.
So is the rear O2sensor the only one that controls long term fuel adaptation, or can it be deleted and the long term fuel adaptation still function?
