The bank 2 sensor 1 on your Jeep Liberty is a technical term used to describe the upstream oxygen sensors on the 3.7-liter engine. Your Liberty has four oxygen sensors, two upstream and two downstream. The sensors monitor the exhaust leaving the engine and communicate directly with the power control module within the Jeep. The power control module, or PCM, collects the details from the sensors and uses the information to determine the air-fuel ratio needed for maximum performance of the engine. Over time, carbon deposits build up on the sensors and may affect the data sent to the PCM as a result. If you suspect that the bank 2 sensor 1 on your 2003 Liberty is defective, you can locate and replace it right at home.
Open your Liberty’s door and apply the emergency brake. Locating the bank 2 sensor 1 will require close contact with the engine and exhaust system. If you have just driven your Liberty within the previous hour, wait another full hour before you continue. This will allow for sufficient cooling of the engine and exhaust system to prevent you from being burned.
Raise the front end of your Liberty with a hydraulic jack. The bottom of both of the front tires should measure no more than 7 inches from the ground. Position a jack stand under the frame rail behind each of the front tires.
Lift the support arms on both of the jack stands to 95 percent of the height needed to actually make contact with the frame rail. Lock the support arms into position at their current height. Begin slowly lowering your Liberty down onto the jack stands. Once you see that the jack stands completely bear your Liberty’s weight, lower and remove the hydraulic jack entirely.
Put on a pair of safety glasses and slide under your Liberty from the front bumper at the center of the engine. Look toward the rear of your Jeep and locate the muffler. Follow the exhaust pipe connected to the muffler toward you. Just before the exhaust pipe reaches the engine, you will see that it splits into two.
Reposition yourself so that you’re able to see the exhaust pipe on the passenger’s side of the engine. Follow the exhaust pipe up to where it connects on the lower side of the engine. You should see a medium-sized, round component connected to the pipe. This is your Liberty’s mini catalytic converter. Just above the catalytic converter, you should see a wiring harness connected to a small capsule-like device. This is the 2003 Jeep Liberty’s oxygen sensor, or bank 2 sensor 1.
Remove your Liberty’s bank 2 sensor 1 by first unplugging the wiring harness connected to it. Unscrew the sensor from the exhaust pipe with a suitable box-end wrench. If upon inspection, the sensor appears overly contaminated by carbon buildup, you should consider replacing your Liberty’s other three oxygen sensors as well.
