Circuit/System Verification
- Allow the engine to reach operating temperature. With the engine running, observe the HO2S parameter with a scan tool. The HO2S 1 value should vary from approximately 40 mV to approximately 900 mV, and respond to fueling changes.
- The normal Short Term FT parameter should be moving rapidly between +10 percent and -10 percent, with near 0 percent the optimum, with the engine running at operating temperature.
- The Long Term FT parameter should be moving slowly between +10 percent and -10 percent, with near 0 percent the optimum, with the engine running at operating temperature. A larger negative value may be present if EVAP purge is enabled