Patent Number: 6,308,697

Title: Method for improved air-fuel ratio control in engines

Abstract: An engine control system of an internal combustion engine coupled to a NOx trap uses a measured air-fuel ratio downstream of the NOx trap to control engine air-fuel ratio. The measured air-fuel is only used for feedback when it indicates a value away from stoichiometry. Thus, NOx and oxygen storage effects that cause inlet air-fuel ratio to be different from exit air-fuel ratio do not cause degraded feedback air-fuel ratio control.

Inventors: Surnilla; Gopichandra (West Bloomfield, MI), Bidner; David Karl (Livonia, MI)

Assignee: Ford Global Technologies, Inc.

International Classification: F02D 41/14 (20060101); F02D 41/02 (20060101); F01N 3/08 (20060101); F02B 075/10 (); F02D 041/14 ()

Expiration Date: 10/30/2018