Fuel trim is based on O2 sensor inputs. The catalytic converter works best at 450 mV = 14.7 to 1. You have 2 different beds in the catalytic converter, part of the time you have to go slightly richer and part of the time slightly leaner. Learn the ins and outs of o2 sensors, catalytic converts, and rich and lean fuel trim with Jim Wilson!
Related Course
Fuel Trim Diagnostics
View CourseIn this program Jim Wilson shows you how to use fuel trim as a diagnostic tool to test certain sensors and to verify your auto repairs. He explains how things like high mileage, dirty injectors, lazy O2 sensors or coking affect short term fuel trim. He also shows you how and what sensors affect fuel trim and how the catalytic converter is involved.
