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Lambda Control

  1. With engine at operating temperature, pull off purge line to throttle valve housing. Plug valve line. Connect on-off ratio tester to diagnostic socket. Press "100%" IR button.
  2. Test on-off ratio at 2500 RPM and read mean value. Compare this value with the idle speed value. The mean value at idle speed must be between 5-15% higher than the mean value measured at 2500 RPM. If not okay, go to step 3). If okay, test is complete.
  3. If reading is constant, test oxygen sensor or repair interruption as necessary. See OXYGEN SENSOR  test in this section. If mean value is not 5 to 15% higher, adjust lambda control.