I just ran the self-diagnostic on my newly acquired caddy after the service engine soon light came on. The description for E046 was "Right to Left Bank Fueling Difference", what should I check to replace?
It means, that one fuel injectors rail inject different amount of fuel.
I think you need clean those rails and maybe have injectors controlled.
I had same readings in last winter - i just add bottle of injector cleaner to gasoline, and it helps.