I have the code p0139. replaced o2 twice, need to track down the wiring. does anyone have some advice?

No code tells you to replace a part , need to do diagnostic's for said code .
P0141 - O2 Heater Circuit (Bank 1, Sensor 2) Description: See the description for DTC P0135. Possible Causes: See the possible causes for DTC P0135. Diagnostic Aids: See the diagnostic aids for DTC P0135. Application Key On Engine Off Key On Engine Running Continuous Memory All GO to Pinpoint Test DW .
DW: Heated Oxygen Sensor (HO2S) DW: Introduction DW1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) Are DTCs P0040, P0041, P0053, P0054, P0055, P0059, P0060, P0132, P0133, P0135, P0138, P0139, P0141, P0144, P0147, P0152, P0153, P0155, P0158, P0159, P0161, or P1127 present?
Yes No For DTCs P0040 or P0041, GO to DW2 .

For DTCs P0053, P0054, P0055, P0059 or P0060, GO to DW14 .

For DTCs P0132, P0138, P0144, P0152 or P0158, GO to DW20 .

For DTCs P0133 or P0153, GO to DW3 .

For DTCs P0135, P0139, P0141, P0147, P0155, P0159 or P0161, GO to DW9 .

For DTC P1127, GO to DW19 . For all others, GO to Section 4, Diagnostic Trouble Code (DTC) Charts and Descriptions .
DW9 DTCS P0135, P0139, P0141, P0147, P0155, P0159 OR P0161: CHECK FOR A SOURCE OF POTENTIAL HO2S CONTAMINATION

• Investigate the following items as potential sources of HO2S contamination:
  • use of unapproved silicon sealers
  • fuel contaminated by silicon additives
  • excessive oil consumption
  • glycol leaking internally in the engine
  • lead-contaminated fuel
  • short drive cycles in cold weather
  • use of unapproved cleaning agents

Is a concern present?
Yes No REPAIR the source of the contamination.

CHANGE the engine oil and oil filter.

RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM) .

REPEAT the self-test. GO to DW10 .

Go to http://bbbind.com/free_tsb.html free wiring diagrams .

Probably replaced a good sensor. This codes could be from a bad sensor, a vacuum leak, or an exhaust leak before the sensor.

Causes
A code P0139 may mean that one or more of the following has happened: The oxygen sensor is faulty The wiring to the sensor is broken / frayed There is an exhaust leak


Possible Solutions

The simplest thing to do is to reset the code and see if it comes back.

If the code comes back, the problem is more than likely the rear driver's side oxygen sensor. You will likely wind up replacing it but you should also consider these possible solutions:

Check and fix any exhaust leaks
Check for wiring problems (shorted, frayed wires)
Check the frequency and amplitude of the oxygen sensor (advanced)
Check for a deteriorating / contaminated oxygen sensor, replace if necessary Check for inlet air leaks
Check the MAF sensor for proper operation

P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
P0325 Knock Sensor 1 Circuit (Bank 1 or Single Sensor) -Circuit Malfunction
think you just need a new o2 sensor

PO139:O2 Sensor ckt Slow Response(Bank 1,sensor 2).This would be the odd side cylinders(1,3,5) and the 2nd oxygen sensor form the cylinder head.The sensor may be contaminated,or the heating element(on a 3 or 4 wire sensor) may not be working well.a good auto parts store should be able to show you a picture of where it is(the store will probably give you a printout if you buy the part form them!)

bank 1 sensor 2. yes it is after the catalytic converter

P0138 - Oxygen Sensor Circuit High Voltage (Bank1, Sensor2)

P0139 - Oxygen Sensor Circuit Slow Response (Bank1, Sensor2)

The Heated Oxygen Sensor (1 or 2) located rear of catalytic converter produces an output signal relative to oxygen storage capacity of catalytic converter. Ho2S 2 signal is less active than signal produced by front oxygen sensor. This code sets when HO2 Sensor voltage is greater than 999 mV for more than 2 minutes (time depends on model. Could be as high as 4 minutes)

Symptoms: There may be no noticeable symptoms except for MIL illumination. Possible high fuel pressure can over rich the system.

Causes: A code P0138 may mean that one or more of the following has happened:
* Faulty O2 sensor
* Short to battery voltage in O2 sensor signal circuit
* High fuel pressure (not as likely)

Here are some potential solutions:
* Replace O2 sensor
* Repair short to battery voltage in o2 sensor signal circuit

Hope helps (remember to rate this answer).

Hi Garcha,

Both codes relate to O2 Sensor # 2

Code P0139: O2 Sensor Circuit Slow Response - Bank 1, Sensor 2
Code P0140: O2 Sensor Circuit No Activity Detected - Bank 1, Sensor 2

A faulty O2 sensor will mean incorrect signals will be sent to the EFI computer, causing erratic engine running.


Cheers,


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Hi the code P0139 is Bank 1 sensor 2 lambda sensor fault ,possible wiring or sensor fault even if you replace the sensor you need to have the MIL lamp turned off by a Diagnostic machine,it is possible you have another fault such as poor Catalytic converter efficency giving the same fault code ,Would recomend you get the car checked and read the "live" data as the car see`s it to make an accurate diagnosis and cure