I can't get rid of code PO131. CHANGED SENSOR TWICE, checked harness for power, it gets power, sensor heater is good, but the sensor GROUND goes high then changes to low, then goes high.
is my ECU fried??????

anyone with same problem?
how did you fix it, or can I double check the sensor with new steps from a professional from this forum?

 

I have a 01 civic and the same code was what I got. I took to my mechanic and he did some tests. I need a new ecu.