P1144 Possible Causes
- Faulty heated oxygen sensor upstream, bank 1
- Open or short circuit in the upstream heated oxygen sensor bank 1 wiring harness
- Poor electrical connection in the upstream heated oxygen sensor bank 1 circuit
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks may be defective
- Exhaust gas leaks
How is P1144 Code Repaired?
Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
- Engine light on (or engine service warning light soon)
P1144 Meaning
The upstream heated oxygen sensor (or O2 sensor 1) is placed in the exhaust manifold. It detects the amount of oxygen in the exhaust gases compared to the outside air. Heated oxygen sensor 1 has a closed-end zirconia ceramic tube. Zirconia generates a voltage from about 1V in richer conditions to 0V in leaner conditions. The signal from heated oxygen sensor 1 is sent to the engine control module (ECM). The ECM adjusts the fuel injection pulse duration to achieve the ideal air-fuel ratio. The ideal air-fuel ratio occurs near the sharp change from 1V to 0V.