Detection of cylinder-to-cylinder air/fuel imbalance

摘要

An air/fuel imbalance detection module includes a fueling control module, a response time determination module, and a comparison module. The fueling control module commands a fueling change according to a predetermined fueling pattern. The response time determination module determines a measured response time for a wide-range air/fuel sensor (WRAF) to output a predetermined voltage. The comparison module compares the measured response time with a reference time range and diagnoses air/fuel imbalance when the measured response time is outside the reference time range.