Conditions for Setting the DTC

If the ECM detects that the rear HO2S voltage is more than 650 mV for more than 100 seconds, then an intrusive test is performed. The ECM will lean the fuel mixture up to -7 percent and then wait for 10 seconds at -7 percent. If the ECM detects that the HO2S voltage is still more than 650 mV, the ECM then test the HO2S at the next decel fuel cut-off. If the ECM detects the HO2S voltage is more than 200 mV after 4 seconds in decel fuel cut-off, this DTC sets.