Method and system for monitoring fuel delivery of an engine

A system for monitoring fuel delivery to an internal combustion engine and controlling the engine accordingly, the engine having a first and second mode of operation and emitting exhaust gas, the system comprising:

• a sensor for sensing an oxygen content of the exhaust gas and generating a corresponding oxygen content signal;
• and
• control logic operative to determine air fuel ratio correction data based on the oxygen content signal, compare the air fuel ratio correction data to a first set of predetermined air fuel ratio correction thresholds to obtain a first signal if the engine is operating in the first mode, compare the air fuel ratio correction data to a second set of predetermined air fuel ratio correction thresholds if the engine is operating in the second mode, and control the engine based on the first and second signals.

An article of manufacture for use with an engine having a first and second mode of operation and having a sensor positioned in the engine exhaust upstream of a catalytic converter for sensing an oxygen content of the exhaust gas and generating an oxygen content signal, comprising:

• a computer storage medium having a computer program encoded therein for causing a computer to control the engine, the computer program for determining air fuel correction data based on the oxygen content signal, comparing the air fuel ratio correction data to a first set of predetermined air fuel ratio correction thresholds to obtain a first signal if the engine is operating the first mode, comparing the air fuel ratio correction data to a second set of predetermined air fuel ratio correction thresholds to obtain a second signal if the engine is operating in the second mode, and controlling the engine based on the first and second signals.