Quote Originally Posted by GasGuzzler View Post
It should nit set those DTC's if the rear O2's were deleted and yes, they're setting because the cats are gone. As far as the lean code, it's kinda rare for one side only to set so look at anything on that bank that could cause a lean condition.
So possibly it might have been a mistake on tuning?

How would I look at the bank? Just check the sensor?