P0144 Code Meaning and Next Steps

First checks take 10 to 15 minutes for the first checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!The engine is misfiring, stalling, or the check-engine light starts flashing.
!There is a strong exhaust smell or a drivability change that suggests a bigger fault than the sensor alone.

If the light is steady and the vehicle still drives normally: Often yes for a short time, but it should not be ignored.

What to check first

Step-by-step checks

1
Free - no tools
Check whether the engine smells rich or has any misfire or fuel-system codes stored with it
2
Free - no tools
Inspect the sensor connector and harness for heat damage or contamination
3
Basic tool needed
Look for a leaking injector or overly high fuel pressure before replacing the sensor
4
Basic tool needed
If the exhaust has been worked on recently, confirm there is no leak or contamination near the sensor
5
Basic tool needed
If scan data is available, compare sensor behavior against short- and long-term fuel trims

If the code returns

-If the mixture issue is fixed and the signal stays high, the sensor or wiring becomes more likely.
-If the code returns after a sensor replacement, go back to the rich-running side first.
-If the engine clears up after a fuel-system repair, that is the stronger clue.

Background

What this code means

P0144 is a generic OBD-II oxygen-sensor code for bank 1 sensor 3.

A high signal can come from rich running, sensor bias, or a wiring fault that makes the sensor look stuck high.

Rich exhaust smell, poor fuel economy, or a signal that seems stuck high on live data can fit this code.

Diagnosis

Common causes

Most common

Rich-running condition

Excess fuel can push the sensor signal high.

Common

Leaking injector

A dribbling injector can keep the bank rich.

Common

Sensor bias

The sensor itself can drift high without a true mixture fault.

Possible

Wiring fault

A signal or reference problem can make the reading look too high.

Avoid these mistakes

What not to do

xDo not replace oxygen sensors first if there is an obvious exhaust leak or mixture problem.
xDo not ignore rough running just because the code names a sensor.

Parts

Parts that may need replacing

PartTypical costNotes

Oxygen sensor$50-$180Relevant when the sensor proves biased after mixture checks.

Fuel injector$40-$180 eachWorth checking if a leak-down test or fuel smell points to one injector.

Connector pigtail repair$15-$90Relevant if heat damage or corrosion is present.

Related OBD codes

P0142

P0142 usually means the bank 1 sensor 3 oxygen sensor circuit is not behaving correctly.

P0143

P0143 usually means the bank 1 sensor 3 oxygen sensor is reading too low.

P0172

P0172 usually means bank 1 is running too rich.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0144 was expanded around common high bank 1 sensor 3 signal faults, including rich running, injector leakage, and wiring issues.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0144 - P0144 Usually Means the Bank 1 Sensor 3 Oxygen Sensor Is Reading Too High