I'm getting a P0161 code and new sensors aren't solving the issue.

[Mike67]

I have replaced the sensor twice and the first replacement coded again before I got out of the driveway, the second one lasted 10-15 miles and then coded again after I went through an automated car wash. IDK if the car wash caused it or if it was just a coincidence. My tuner thinks I have a bad wire or connection somewhere causing it. I checked the pins on the female connector where the O2 sensor plugs into last time and they looked good to me so that leads me to believe it's upstream from the connector.

If I could get my hands on a wiring diagram for the car that would be great. Any recommendations on where to look and how to track the problem down would really be appriciated.

2017 Taurus SHO

 

[Ta2dResqr]

White is hot in start/run. Black is signal in and grey is return.

 

[luigisho]

since it is a heated sensor code that usually that looks looks like sensor or wiring failure. Maybe an exhaust leak or bad cat but I would look at electrical as most likely. I don't have the electrical specs but hopefully someone here has access to a file with that info and the schematic for that circuit.

 

[rubydist]

Hopefully these help.

 

[SHOdded]

did you use a ford/motorcraft sensor? any oil leaking onto either of the bank 2 sensors? battery tests ok? connectors at pcm look good n clean?

Gasoline Engines PCED
P0161 - O2 Heater Circuit (Bank 2, Sensor 2)

Description: ​	This DTC sets when an open or short circuit is detected or the universal heated oxygen sensor bank 2, sensor 2 (HO2S22) heater current draw exceeds a calibrated limit.​
Possible Causes: ​	HTR22 circuit open HTR22 circuit short to voltage VPWR circuit open GND circuit open Low battery voltage Water in the harness connector Corrosion Incorrect connections Damaged HO2S22 heater

Gasoline Engines PCED

DW13 CHECK FOR VPWR​

• Note: Diagnose the suspect sensor indicated by the DTC.
• Ignition OFF.
• For HO2S12,
• HO2S12 connector disconnected.
• Ignition ON, engine OFF.
• Measure the voltage between:
  
  

  ( + ) HO2S12 Connector, Harness Side​	( - )​
  VPWR​	Ground​

• For HO2S22,
• HO2S22 connector disconnected.
• Ignition ON, engine OFF.
• Measure the voltage between:
  
  

  ( + ) HO2S22 Connector, Harness Side​	( - )​
  VPWR​	Ground​

Is the voltage greater than 10.5 V?

Yes	No
GO to DW14 .	REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

DW14 CHECK THE HO2S HEATER CIRCUIT FOR AN OPEN​

• Ignition OFF.
• PCM connector disconnected.
• For HO2S12,
• Measure the resistance between:
  
  

  ( + ) HO2S12 Connector, Harness Side​	( - ) PCM Connector, Harness Side​
  HTR12​	HTR12​

• For HO2S22,
• Measure the resistance between:
  
  

  ( + ) HO2S22 Connector, Harness Side​	( - ) PCM Connector, Harness Side​
  HTR22​	HTR22​

Is the resistance less than 5 ohms?

Yes	No
GO to DW15 .	REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

DW15 CHECK THE HO2S HEATER FOR SHORT CIRCUITS​

• For HO2S12,
• Measure the resistance between:
  
  

  ( + ) HO2S12 Connector, Harness Side​	( - )​
  HTR12​	Ground​

• Measure the resistance between:
  
  

  ( + ) HO2S12 Connector, Harness Side​	( - ) HO2S12 Connector, Harness Side​
  HTR12​	VPWR​
  HTR12​	SIGRTN​
  HTR12​	HO2S12​

• For HO2S22,
• Measure the resistance between:
  
  

  ( + ) HO2S22 Connector, Harness Side​	( - )​
  HTR22​	Ground​

• Measure the resistance between:
  
  

  ( + ) HO2S22 Connector, Harness Side​	( - ) HO2S22 Connector, Harness Side​
  HTR22​	VPWR​
  HTR22​	SIGRTN​
  HTR22​	HO2S22​

Are the resistances greater than 10K ohms?

Yes	No
GO to DW16 .	REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.

DW16 CHECK THE INTERNAL RESISTANCE OF THE HO2S HEATER​

• For HO2S12,
• Measure the resistance between:
  
  

  ( + ) HO2S12 Connector, Component Side​	( - ) HO2S12 Connector, Component Side​
  HTR12​	VPWR​

• For HO2S22,
• Measure the resistance between:
  
  

  ( + ) HO2S22 Connector, Component Side​	( - ) HO2S22 Connector, Component Side​
  HTR22​	VPWR​

Is the resistance between 2 - 30 ohms?

Yes	No
GO to DW17 .	INSTALL a new HO2S. REFER to the Workshop Manual Section 303-14, Electronic Engine Controls. RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM) . REPEAT the self-test.

DW17 CHECK THE HEATER CIRCUIT FOR AN INTERNAL SHORT TO GROUND​

• For HO2S12,
• Measure the resistance between:
  
  

  ( + ) HO2S12 Connector, Component Side​	( - ) HO2S12 Connector, Component Side​
  HTR12​	SIGRTN​

• Measure the resistance between:
  
  

  ( + ) HO2S12 Connector, Component Side​	( - )​
  HTR12​	Ground​

• For HO2S22,
• Measure the resistance between:
  
  

  ( + ) HO2S22 Connector, Component Side​	( - ) HO2S22 Connector, Component Side​
  HTR22​	SIGRTN​

• Measure the resistance between:
  
  

  ( + ) HO2S22 Connector, Component Side​	( - )​
  HTR22​	Ground​

Is the resistance greater than 10K ohms?

Yes	No
GO to DW18 .	INSTALL a new HO2S. REFER to the Workshop Manual Section 303-14, Electronic Engine Controls. RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM) . REPEAT the self-test.

DW18 CHECK FOR CORRECT PCM OPERATION​

• Ignition OFF.
• Disconnect all the PCM connectors.
• Visually inspect for:
  • pushed out pins
  • corrosion
• Connect all the PCM connectors and make sure they seat correctly.
• Carry out the PCM self-test.
• Verify the concern is still present.

Is the concern still present?

Yes	No
INSTALL a new PCM. REFER to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) , Programming the VID Block for a Replacement PCM.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

 

[luigisho]

Replys like these in short time periods... I really love this forum.