Having a strange problem with bank A and B upstream O2 sensors. Bank A is at "0" volts, bank B is so erratic I can't get a fix on the voltage. Downstream sensors are both working fine. I changed out both upstream sensors (Denso), bank A had a bad harness plug that I changed out. No change at all. Anyone encountered this problem before?
Front o2 sensor trouble
- Thread starter mearstrae
- Start date
I should have said it is a D2, 4.6L. Anything's worth a try, I have a bad feeling it's in the wiring harness or the ECU itself.
Can you actually see what the sensors are reading(Testbook/Rovacom/ect) or are you just using a volt meter?
Sounds silly but check ALL fuses interior and exterior before getting crazy with the harness.
Sounds silly but check ALL fuses interior and exterior before getting crazy with the harness.
Make sure you got the pins right on your "rewiring" of plug A.
Swap the upper sensor plugs with one another. You don't have to physically move the sensors just swap connections and see if the "0" volts follows the sensor.
Swap the upper sensor plugs with one another. You don't have to physically move the sensors just swap connections and see if the "0" volts follows the sensor.