Conditions for Setting the DTC

Conditions 1

• The ECM detects that the front HO2S is operating too lean while the rear HO2S is operating too rich and the ECM detects that the fuel trim is at maximum control.

  OR

• The rear fuel trim, long and short term, is greater than a threshold.
• This DTC sets after the air flow coming into the engine accumulates to greater than 200 rams and the above conditions are met for greater than 4 seconds.

Conditions 2

• The ECM detects that the rear HO2S is operating too rich while the ECM is commanding a lean air/fuel mixture.
• This DTC sets after the air flow coming into the engine accumulates to greater than 800 grams and the above condition is met for greater than 4 seconds.