System and method for adjusting air/fuel ratio

摘要

The invention relates to a new method and system for optimizing the efficiency of an automotive catalytic converter. The claimed invention comprises adjusting an air/fuel ratio in the cylinders of an internal combustion engine to maintain a desired level of oxidants in the catalytic converter. At various times, the actual amount of oxidants stored in the catalytic converter is determined. The actual oxidant amount is compared to a target amount of oxidants to be stored in the catalytic converter. The air/fuel ratio in the cylinders is adjusted based on magnitude of the difference between the actual oxidant amount and the target oxidant amount to prevent NOx and hydrocarbon breakthrough.