Abstract: A method of load and speed modifying on fuel lean-out for an internal combustion engine includes the steps of sensing a speed of the engine, determining an engine speed modifier as a function of current sensed engine speed, sensing a manifold absolute pressure (MAP) of an intake manifold of the engine, determining an engine load modifier as a function of current sensed MAP, adding the determined engine speed modifier and engine load modifier together to yield a speed/load modifier, and applying the speed/load modifier value to a fuel pulsewidth value of fuel injectors for the engine and reducing the amount of fuel injected into the engine by the fuel injectors.

Abstract: A method of proportional deceleration fuel lean-out for an internal combustion engine includes the steps of sensing a throttle position of a throttle for the engine with a throttle position sensor, calculating a throttle proportional deceleration fuel lean-out multiplier (LOTHR) value based on the sensed throttle position, sensing a manifold absolute pressure (MAP) of an intake manifold for the engine with a MAP sensor, calculating a MAP proportional deceleration fuel learn-out multiplier (LOMAP) value based on the sensed MAP, combining the LOTHR and LOMAP values and calculating an overall proportional deceleration fuel lean-out multiplier (LOMULT) value, and applying the calculated LOMULT value to a fuel pulsewidth value of fuel injectors for the engine and reducing the amount of fuel injected into the engine by the fuel injectors.

Abstract: A method of catalyst purging (run-time) fuel lean-out for an internal combustion engine including the steps of determining whether the engine is in a throttle deceleration condition or a MAP deceleration condition, sensing a speed of the engine, determining whether the current sensed engine speed is above a predetermined speed if the engine is in a throttle or MAP deceleration condition, determining a magnitude of a run-time lean-out multiplier (RTLEAN) value if the current sensed engine speed is above the predetermined speed, and applying the determined RTLEAN value to a fuel pulsewidth value of fuel injectors for the engine and reducing the amount of fuel injected into the engine by the fuel injectors.

Abstract: A method of averaging coolant temperature for an internal combustion engine in an automotive vehicle includes the steps of sensing coolant temperature of the engine based on an output signal of a coolant temperature sensor, determining an initial value of coolant temperature based on the output signal from the coolant temperature sensor, storing the determined initial value as an initial coolant temperature value (CLTMP1) and as an averaged coolant temperature value (AVCT), periodically updating the AVCT value, and using the AVCT value to control the output of fuel injectors of the engine.