Air/fuel ratio feedback control system for an internal combustion engine.

摘要

An engine air/fuel control method involves measuring nitrogen oxide content of exhaust gases downstream of the catalytic converter to generate a first measurement signal. Combined hydrocarbon and carbon monoxide content in exhaust gases downstream of the catalytic converter are measured to generate a second measurement signal, and the first measurement signal is subtracted from the second measurement signal to generate a third signal. A correction signal is generated from an exhaust gas oxygen sensor positioned upstream of the catalytic converter. The fuel delivered to the engine is corrected by the feedback variable.