P0131/p0165

[RELL1274]

Hello Ford Friends I Need Help My Wife Has A 97 Taurus I Just Changed The Speed Sensor And That Works Fine A Day After That The Service Light Came On I Got P0131 And P0165 And I Cant Figure Out What The Problem Is Can Any One Help..

[RoB51988]

P0131 means your O2 sensor's voltage isnt high enough, probably because aof a short. It could also mean that your O2 sensor is just broke and needs to be replaced. This sensor is right infront of the catalytic converter.

Not really sure what a P0165 is.

[shorod]

Hmmm, check those codes again. P0165 02 Sensor Circuit Slow Response (Bank 2 Sensor 3). Your '97 Taurus will not have a 3rd Bank 2 O2 sensor.

-Rod

[shorod]

P0131 means the heated oxygen sensor (H02S) for bank 1, sensor 1, has been logged generating a negative voltage. According to the factory service manual, this can possibly be caused by:
Possible causes:

-- Contaminated HO2S (water, fuel, etc.).

-- Crossed HO2S signal/signal return wiring.

The factory service manual agrees, P0165 is not applicable to your 1997 Taurus. You need to recheck the codes and verify that one. Was it by chance a P1650? According to the factory service manual:

Diagnostic Trouble Code (DTC) P1650 indicates Power Steering Pressure (PSP) signal out of Self-Test range. DTC P1651 indicates PSP signal malfunction.

Possible causes:

-- PSP switch/shorting bar damaged.

-- SIG RTN circuit open or shorted to GND.

-- PSP circuit open or shorted to SIG RTN.

-- PCM damaged.

It doesn't seem like much of a stretch to think you could have one wiring issue causing both such codes.

-Rod

[shorod]

Based on your private message, I understand that the codes you are currently getting are P0135 and P0161. This makes more sense as both codes are somewhat related.

Per the factory service manual (FSM), Diagnostic Trouble Codes (DTCs) P0135, P0141, P0155 and P0161 indicate a short to ground, open, or short to VPWR in the HO2S heater circuit.

DTC/HO2S Reference List:

DTC P0135 = HO2S HTR-11
DTC P0141 = HO2S HTR-12
DTC P0155 = HO2S HTR-21
DTC P0161 = HO2S HTR-22

The list above would indicate you have an issue on Bank 1, sensor 1 and Bank 2, sensor 2.

Also according to the FSM, possible causes for these codes are:

-- Shorts to B+ in harness or HO2S.
-- Water in connectors.
-- Cut or pulled wires.
-- Disconnected wiring.
-- Open VPWR circuit.
-- Open GND circuit.
-- Low battery voltage.
-- Corrosion or poor mating terminals.
-- Damaged HO2S heater.
-- Damaged PCM.

It appears the power to all 4 of the oxygen sensor is through the transmission range sensor (TRS) which has been known to cause a lot of electrical gremlins. However, it would seem all four sensors should exhibit issues if the TRS were the issue.

-Rod