Check Engine Light came on, I went to Advanced Auto and their scanner showed those two codes (O2 sensor). I'm pretty sure that there isn't anything wrong with the O2 sensor and that something is causing them to throw a code, but I'm not sure what to check first. It's a completely stock '03 GT, automatic.
Code P0156 and Code P0161
- Thread starter Moon
- Start date
wmburns
SN Certified Technician
If asking for someone to handicap this thread, my vote is the transmission wiring harness has been damaged.
Start first with an inpection of the wiring to the rear O2 sensors. Pay special attention to the Left hand (driver's) side O2 sensor.
Good call on the diagnosis. I agree with you that it's likely the O2 sensors themselves are OK.
>>
P0156 - HO2S Sensor Circuit Malfunction (HO2S-22)
Pinched, shorted, and corroded wiring and pins.
Crossed sensor wires.
Exhaust leaks.
Contaminated or damaged sensor.
P0161 - HO2S Sensor Circuit Malfunction (HO2S-22)
Short to VPWR in harness or HO2S.
Water in harness connector.
Open VPWR circuit.
Open GND circuit.
Low battery voltage.
Corrosion or poor mating terminals and wiring
Damaged HO2S heater.
Damaged PCM.
Start first with an inpection of the wiring to the rear O2 sensors. Pay special attention to the Left hand (driver's) side O2 sensor.
Good call on the diagnosis. I agree with you that it's likely the O2 sensors themselves are OK.
>>
P0156 - HO2S Sensor Circuit Malfunction (HO2S-22)
Pinched, shorted, and corroded wiring and pins.
Crossed sensor wires.
Exhaust leaks.
Contaminated or damaged sensor.
P0161 - HO2S Sensor Circuit Malfunction (HO2S-22)
Short to VPWR in harness or HO2S.
Water in harness connector.
Open VPWR circuit.
Open GND circuit.
Low battery voltage.
Corrosion or poor mating terminals and wiring
Damaged HO2S heater.
Damaged PCM.
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