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GTECH Calibration
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P1144

HO2S Bank 1 Sensor 3 Rich Or High Voltage.

  • GMC
  • Powertrain
  • Manufacturer code
  • Low severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
1
AreaFuel and air metering
44
FaultThe specific fault in that area

What it means

P1144 on a GMC means the control unit has seen the Bank 1 Sensor 3 heated oxygen sensor reporting a rich mixture or a voltage that stays high. Sensor 3 is normally the sensor fitted downstream of the main catalytic converter, so what it reads reflects exhaust leaving the catalyst. The exact sensor position depends on the model and exhaust layout, so confirm it for your vehicle.

Symptoms

  • Check engine light on
  • Possible smell of fuel or rich exhaust
  • Poor fuel economy
  • Rough running or hesitation if a real rich condition exists
  • Often no noticeable change in driveability

Possible causes

  • Faulty or contaminated Bank 1 Sensor 3 oxygen sensor reading highlikely
  • Damaged wiring or a short to voltage in the sensor signal circuitlikely
  • Corroded or loose connector at the sensor or control unitpossible
  • Genuine rich running from a fuel delivery fault such as leaking injectors or high fuel pressurepossible
  • Catalytic converter not working efficiently, giving unusual downstream readingspossible
  • Exhaust leak near the sensor or silicone/coolant contamination of the sensorrare
  • Control unit fault or outdated calibration, where a manufacturer bulletin appliesrare

How to diagnose

  1. Read all stored and pending codes and note the freeze frame data, including engine temperature, load and fuel trims
  2. Check for other fuel trim, misfire or upstream oxygen sensor codes that point to a genuine rich condition
  3. Inspect the sensor wiring and connector for chafing, heat damage, corrosion and water ingress
  4. View live data for Bank 1 Sensor 3 and see whether the voltage sticks high or responds to changes in throttle
  5. Check short and long term fuel trims at idle and at steady cruise to see if the engine is truly running rich
  6. Check for exhaust leaks around the sensor and inspect the sensor for contamination from coolant or oil
  7. Test the sensor signal and heater circuits for shorts to voltage and for correct reference and ground, following the wiring diagram for your model
  8. Check fuel pressure and injector condition if trims confirm a rich condition

How to fix

  • Replace the Bank 1 Sensor 3 oxygen sensor if it is faulty or contaminated
  • Repair or replace damaged wiring and clean or renew corroded connector terminals
  • Fix the underlying fuel fault, such as a leaking injector or faulty pressure regulation, if the mixture is truly rich
  • Repair any exhaust leak near the sensor
  • Replace the catalytic converter only if testing shows it has failed
  • Update the control unit calibration only if a known fault or manufacturer bulletin applies to your vehicle

Can I keep driving?

Low severity

The car can usually be driven short term and booked in for diagnosis. If it runs badly, smells strongly of fuel or the engine light flashes, limit driving, as a genuine rich condition can damage the catalytic converter.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.

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