Jeep introduced the Liberty SUV in 2002 as a replacement for the discontinued Cherokee. Four-wheel disc brakes were added to the Liberty in 2003. Available in either two- or four-wheel-drive, the 2003 Liberty was powered by a 2.4-liter inline four-cylinder or 3.7-liter V-6 engine. The V-6 engines with California emissions use four sensors -- two on each bank. One sensor is placed in front of and behind each mini-catalytic converter. All four-cylinder and non-California V-6s use two sensors on one bank, with one sensor in front of, and one behind the main converter.
Items you will need
- Jack stands
- Oxygen sensor socket
- Torque wrench
Location and RemovalStep 1
Park the Liberty on a level, paved surface and set the parking brake. Raise the front of the Liberty and support with jack stands. Allow the engine to cool down so you don't burn yourself on hot exhaust components.
Move under the passenger side of the engine and follow the exhaust pipe up towards the engine. You will see two sensors in the pipe – one before, or on top of the mini-catalytic converter and one after, or below, the converter – the one before the converter is bank 2 sensor 1.
Disconnect the sensor pigtail from the engine wiring harness. The connector has a locking tab that you must push down to separate the connectors.
Remove the sensor with a ratchet and sensor socket. The socket has a notch in it for the sensor wire -- commonly called a "pigtail."
Thread a new sensor into the exhaust pipe. Do not apply anti-seize or any other compound to the sensor. New sensors come with anti-seize pre-applied.
Tighten the sensor with a torque wrench and the sensor socket to 30 foot-pounds.
Connect the sensor pigtail to the engine harness.
Raise the Liberty, remove the jack stands and lower it to the ground.
- You may need to soak the sensor with penetrating lubricant to get it free. If you replaced the sensor because of a check engine light, either reset the code with a code reader or have it reset at an auto parts store.
- Do not touch or get the sensor tip dirty.
- Auto Zone: 2003 Jeep Liberty 2WD 3,7L SFI SOHC 6cyl/Repair Guides/Components & Systems/heated Oxygen Sensor
- AllData: 2003 Jeep Truck/Liberty 2WD/Powertrain Management/Computers and Control Systems/oxygen Sensor