DTC P0140: 1/2 O2 Sensor Stays At Center: Description

Monitor will run after engine has been running for more than 121 seconds, in closed loop fuel control mode with engine coolant temperature more than 151°F (66°C). DTC will set when 1/2 HO2S voltage is .35-.58 volt for 30 seconds, then 1.5 volts for 60 seconds. Possible causes are: defective 1/2 HO2S, open or high resistance in signal circuit, open or high resistance in sensor ground circuit or defective PCM.