DTC P1133: Ho2S Insufficient Switching - Bank 1, Sensor 1; P1153: Ho2S Insufficient Switching - Bank 2, Sensor 1: Description

PCM monitors Heated Oxygen Sensor (HO2S) activity for 100 seconds. During this period, Powertrain Control Module (PCM) counts number of times that HO2S switches from rich-to-lean and lean-to-rich. A lean-to-rich switch is determined when HO2S voltages changes from less than 300 mV to more than 600 mV. A rich-to-lean switch is determined when HO2S voltage changes from more than 600 mV to less than 300 mV.