METHOD AND SYSTEM FOR IDENTIFICATION AND MITIGATION OF AIR-FUEL RATIO IMBALANCE

摘要

Methods and systems are provided for identifying imbalanced cylinder and mitigating the imbalanced cylinder. In one example, a method may include identifying an imbalanced cylinder based on readings from two exhaust gas oxygen sensors positioned upstream and downstream of a catalyst in an exhaust passage, and mitigating the imbalance based on the magnitude of a fault determined from the readings.

主权项

1. A method for a multi-cylinder engine, comprising:
identifying an imbalanced cylinder based on each of a first sensor positioned upstream of a catalyst and a second sensor downstream of the catalyst, wherein the first and the second sensors are positioned on opposite sides relative to a central axis of an exhaust passage; and adjusting an air-fuel ratio of the imbalanced cylinder via a fuel injector.