Technician a Says That Closed Loop Is the Most Efficient

Multiple Choice

Technician A says that closed loop is the most efficient operating mode and allows the engine computer to control the air-fuel ratio with the most precision. Technician B says that open loop operation is used to improve performance during cold engine warm-up and is also used under heavy load or during wide open throttle operation. Who is correct?

A) Technician A only
B) Technician B only
C) Both technicians
D) Neither technician