Conditions for Setting the DTC

Condition 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 more than a threshold.
• This DTC sets after the air flow coming into the engine accumulates to more than 200 grams and the above conditions are met for more than 4 seconds.

Condition 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 more than 800 grams and the above condition is met for more than 4 seconds.