A system and method for controlling fuel delivery based on an output from a post-catalyst oxygen sensor during a light-off of a catalyst

摘要

A system includes a voltage determination module and measurement module determines a first output voltage of a first oxygen sensor position upstream of a catalyst in an exhaust system of an engine and determines a second output voltage from a second oxygen sensor positioned downstream of the catalyst, which indicates exhaust gas upstream of the catalyst and the second output voltage is indicative of a second oxygen level of exhaust gas downstream of the catalyst. The fuel control module controls a fuel mass that is injected into the engine based on a first output voltage and a second output voltage when a temperature of the catalyst is greater than a light off temperature, and controls the fuel mass based on the second output voltage and independently of the first output voltage, when the catalyst temperature is lower than the light-off temperature.