uberEFtune

car was showing dtc P0171.
The main thing I need to know is why the O2 sensors are not ready and they are not reading any voltage. I tested the voltage at the connector and they are fine. Its like the computer can't see the O2 senesor Also the fuel trim is at 99.2% on the post cat sensor. WTF What is going on with this car????

It drives fine too.

car has 140,000 miles and needed regular maintenance items.
Replaced:
-fuel filter
-valve cover gaskets/spark plugs/upper intake manifold gasket
-thermostat(was stuck open)
-cleaned MAF sensor(measuring proper amount)
-replaced sticky PCV valve
-checked and no vacume leaks.

Drive status since DTC clear
misfire: complete
fuel system: complete
components: complete
catalyst: incomplete
evaporative: incomplete
O2 sensor: incomplete
O2 sensor heater: complete

O2 sensor Bank1 sens1 0volts just replaced
O2 sensor Bank1 sens2 .9volts
O2 sensor Bank2 sens1 0volts just replaced

fuel trim data
F/T Bank1 sens2 99.2%
F/T Bank1 sens1 Nothing showing up
F/T Bank2 sens1 Nothing showing up



Basically nothing is changing after i replaced these things. I was really thinking the O2 sensors were bad beacuase they where not reading any voltage with a scanner. I am scanning with torque connected to elm327 Bluetooth.

uberEFtune

I will answer my own question after doing some research. This model uses air to fuel ratio sensors. So they cannot be seen with a scan tool that looks for typical O2 sensors. I was using the Torque App on my phone with a bluetooth adapter. This works fine for other cars, but not the Lexus.