2006 mustang v6 4.0L cel with code p0155

[kain9090]

I am getting engine code p0155. It idles a little rough and has some trouble accelerating, but otherwise runs great. The car is stock. I have replaced the bank 2 sensor 1 twice with ntk o2 sensors. I have inspected the wiring harness and nothing looks damaged. I also confirmed it is getting the correct voltage. I did also confirm the short term fuel trim is within the right parameters for bank 2, not sure if that matters. The only other thing I could think of is a failing pcm. Any help would be much appreciated thank you

 

[TexasBlownV8]

First of all, you need to understand the failure it is reporting for that sensor: heater circuit. There is 12 volts that feeds the sensor in a red/yellow striped wire, then the return voltage is measured by the pcm to verify operation, i.e. a proper voltage drop across the sensor heater circuit.

Exactly which sensor are you replacing, driver side or passenger side? band 2 is driver side. Sensor 1 is front sensor with green connector. For sensors, especially o2 sensor, I would only use ford/motorcraft sensors.

But before replacing, try swapping the 2 front sensors with each other, clear the code, and see if it changes banks. You'd be able to isolate a defective sensor that way.
If the code returns, the next step would be to check voltage at the PCM connector 175t (the smaller of the 3 pcm connectors), pin 24 red/lt.grn for bank 1, pin 25 violt/lt. green for bank 2. With key on power, they should both save similar voltages.

 

[86GT351]

First of all, you need to understand the failure it is reporting for that sensor: heater circuit. There is 12 volts that feeds the sensor in a red/yellow striped wire, then the return voltage is measured by the pcm to verify operation, i.e. a proper voltage drop across the sensor heater circuit.

Exactly which sensor are you replacing, driver side or passenger side? band 2 is driver side. Sensor 1 is front sensor with green connector. For sensors, especially o2 sensor, I would only use ford/motorcraft sensors.

But before replacing, try swapping the 2 front sensors with each other, clear the code, and see if it changes banks. You'd be able to isolate a defective sensor that way.
If the code returns, the next step would be to check voltage at the PCM connector 175t (the smaller of the 3 pcm connectors), pin 24 red/lt.grn for bank 1, pin 25 violt/lt. green for bank 2. With key on power, they should both save similar voltages.

Very good explanation.

 

[Gorje]

First of all, you need to understand the failure it is reporting for that sensor: heater circuit. There is 12 volts that feeds the sensor in a red/yellow striped wire, then the return voltage is measured by the pcm to verify operation, i.e. a proper voltage drop across the sensor heater circuit.

Exactly which sensor are you replacing, driver side or passenger side? band 2 is driver side. Sensor 1 is front sensor with green connector. For sensors, especially o2 sensor, I would only use ford/motorcraft sensors.

But before replacing, try swapping the 2 front sensors with each other, clear the code, and see if it changes banks. You'd be able to isolate a defective sensor that way.
If the code returns, the next step would be to check voltage at the PCM connector 175t (the smaller of the 3 pcm connectors), pin 24 red/lt.grn for bank 1, pin 25 violt/lt. green for bank 2. With key on power, they should both save similar voltages.

What pins on the pcm connector are the ones for sensor 2 on both banks?