DTC P0031: Ho2S1 Heater Control Circuit Low - Bank 1, DTC P0032: Ho2S1 Heater Control Circuit High - Bank 1, DTC P0051: Ho2S1 Heater Control Circuit Low - Bank 2 Or DTC P0052: Ho2S1 Heater Control Circuit High - Bank 2: Description
WARNING: This page is about a different car, the 2002 Nissan Xterra and 2002 Nissan Frontier. However, it is still accessible from the selected car via links, so may be relevant.
The ECM performs on/off control of HO2S1 heaters based on engine speed. HO2S1 heaters are turned off above 3000 RPM (on 2.4L models) or 3200 RPM (on 3.3L models).