Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
Your car has a sensor that checks how much oxygen is in the exhaust. This code means that one of these sensors isn't working right and is giving a signal that's too low.
The O2 sensor is not providing the expected voltage signal, indicating a potential issue with the sensor or its circuit.
The P1144 code is triggered when the Engine Control Module (ECM) detects that the oxygen sensor located after the catalytic converter (Bank 1 Sensor 2) is not providing a signal within the expected range. This sensor monitors the efficiency of the catalytic converter by measuring the oxygen level in the exhaust gases.
• Check Engine Light is on
• Decreased fuel efficiency
• Failed emissions test
• Faulty O2 sensor
• Wiring issues or poor electrical connections
• Exhaust leaks
O2 Sensor: A device that measures the oxygen level in the exhaust gases.
ECM: Engine Control Module, the computer that controls engine functions.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage.
• Test the O2 sensor with a multimeter.
• Replace the faulty O2 sensor.
• Repair or replace damaged wiring or connectors.
• Fix any exhaust leaks.
• OBD-II scanner
• Multimeter
• Socket set
$150 - $300
Moderate
• Nissan Altima
• Infiniti G35
• Nissan Maxima
• Regularly inspect and maintain the exhaust system.
• Ensure proper connections and wiring integrity.
• Use high-quality fuel to reduce sensor contamination.
Sensor Issue
• Address the issue promptly to avoid further damage.
• Consult a professional mechanic if unsure about repairs.
O2 sensors may be covered under the emissions warranty. Check with your vehicle manufacturer.
This code is commonly associated with aging vehicles where sensors have worn out over time.
Moderate – It should be addressed soon to maintain vehicle performance and emissions standards.
Driving with a faulty O2 sensor can lead to increased emissions and may fail emissions tests required by law.
• Engine at operating temperature
• Vehicle in closed-loop mode
The O2 sensor (Bank 1 Sensor 2) is located after the catalytic converter on the exhaust system of the engine's first bank.
Q: Can I drive my car with this code?
A: You can drive, but it's best to fix the issue soon to avoid poor fuel economy and potential emissions test failure.
Q: How often should O2 sensors be replaced?
A: Typically, O2 sensors should be replaced every 60,000 to 90,000 miles, but check your vehicle's manual for specific recommendations.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Relevant when the code or supporting diagnostics point toward upstream or downstream oxygen-sensor faults.
This code family often involves upstream or downstream oxygen-sensor diagnosis.
Verify exact sensor position and vehicle fitment before buying.
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Fitment Required · Vehicle-fitment part
Relevant when catalyst-efficiency or emissions faults persist after proper diagnosis.
Catalyst-efficiency faults sometimes point toward converter problems after proper testing.
Catalytic converters are highly vehicle-specific and should not be purchased by code alone.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.