Testing Procedure

O2 Signal -  Connect DVOM between ME-SFI control module connector "C" terminals No. 31 and 32 (socket box terminals No. 23 and 24). Start engine and idle. Allow engine to idle for at least 2 minutes after engine coolant temperature reaches more than 176°F (80°C). Voltage should fluctuate by more than 0.3 volts between -0.2 volts and one volt. If voltage is okay, test is complete. If voltage is not okay, possible causes are right O2 sensor (before TWC) heater failure, wiring harness failure or defective right O2 sensor (before TWC - G3/4). To check right O2 sensor (before TWC) heater failure, go to DTC P0135: O2 SENSOR HEATING OF RIGHT O2 SENSOR UPSTREAM TWC (G3/4)  .