Technician A says that the primary purpose of fuel trim is to keep the air-fuel mixture as close to 14.7:1 as possible. Technician B says that when the air-fuel ratio is at 14.7:1, the efficiency of the catalytic converter is the lowest. Which technician is correct?

Question

Quizplus · Accepted Answer

Technician A is correct. The primary purpose of fuel trim is to keep the air-fuel ratio as close to 14.7:1 as possible for optimal engine performance and emissions control. Technician B is incorrect. The efficiency of the catalytic converter is actually highest when the air-fuel ratio is at 14.7:1.

Technician a Says That the Primary Purpose of Fuel Trim