Patent ID: 7665444

Claim:
A system for measuring a normalized air-to-fuel ratio, the system comprising: a first wide-band oxygen sensor in fluid communication with an exhaust stream generated by an internal combustion engine, the first wide-band oxygen sensor configured to detect an oxygen deficit in the exhaust stream; the wide-band oxygen sensor further configured to detect an oxygen surplus in the exhaust stream; at least one oxygen pump configured to pump oxygen into the wide-band oxygen sensor to eliminate a detected oxygen deficit and pump oxygen out of the wide-band oxygen sensor to eliminate a detected oxygen surplus, the at least one oxygen pump being powered by an electrical current; and an oxygen sensor control module matched to the wide-band oxygen sensor and configured to detect the electrical current and provide a volumetric oxygen percentage based on the detected electrical current to an engine control module of the engine, wherein the volumetric oxygen percentage is a positive value if the wide-band oxygen sensor detects one of an oxygen deficit and surplus in the exhaust stream and a negative value if the wide-band oxygen sensor detects the other of the oxygen deficit and surplus in the exhaust stream.