A vehicle is in the shop for diagnosis of a fuel economy complaint. When the memory DTCs are pulled from the PCM, an “O 2 sensor is always lean” code is received. Technician A says that this means...

A vehicle is in the shop for diagnosis of a fuel economy complaint. When the memory DTCs are pulled from the PCM, an “O₂
sensor is always lean” code is received. Technician A says that this means that the O₂
sensor is faulty and should be replaced without wasting any time on further testing. Technician B says that this code does not necessarily mean that the O₂
sensor is faulty. Who is correct?

A. Technician A only

B. Technician B only

C. Both technicians

D. Neither technician