Patents Represented by Law Firm Keck, Main & Cate
  • Exhaust system for internal combustion engine
    Patent number: 5228287
    Abstract: An exhaust system for an automobile engine having two groups of cylinders has a catalytic device. Deterioration of the catalytic device is detected based on an oxygen level in exhaust gas passed through the catalytic device. A feedback control of an air-fuel ratio is conducted for the cylinder groups all together, based on either of the air-fuel ratios determined, based on emission levels of exhaust gas discharged, for one of two of the groups of cylinders, only when a specific vehicle driving condition is detected.
    Type: Grant
    Filed: June 29, 1992
    Date of Patent: July 20, 1993
    Assignee: Mazda Motor Corporation
    Inventors: Kiyoshi Kuronishi, Kazunari Komatsu, Naoyuki Noguchi, Hirofumi Nishimura