Dodge began offering the 5.7-liter HEMI V-8 for the RAM truck in the 2003 model year for most available trim levels. Dodge implemented four oxygen sensors into the exhaust system of the Dodge RAM to monitor the amount of oxygen left over after the combustion process. The onboard computer system uses information received from these oxygen sensors to adjust the air to fuel ratio to help provide optimal performance and emissions. The oxygen sensors are located just before and after the catalytic converter on the left and right exhaust piping.
Things You'll Need
- Floor jack
- Jack stands
- Oxygen sensor socket
- Wire brush
- Propane torch
- 18 mm x 1.5 Tap
- Torque wrench
Park the truck on a level surface and set the parking brake. Lift the front of the truck into the air with a floor jack and place jack stands under the front frame rails. Lower the floor jack until the truck rests securely on the jack stands. Allow the engine to cool completely before continuing.
Position yourself under the truck in a manner that you can observe the oxygen sensor to be removed; there will be one before and after the catalytic converter on both sides of the transmission. Trace the oxygen sensor pigtail from the sensor to its connection at the truck wiring harness. Squeeze the locking tab and separate the pigtail connector from the harness connector.
Install the oxygen sensor socket over the sensor so that the pigtail extends through the slotted opening in the sensor socket. Attach a ratchet to the socket and rotate counterclockwise to remove the sensor. Apply heat from the propane torch to the exhaust piping base around the oxygen sensor if the sensor will not loosen. Remove the sensor socket once the sensor is loose. Remove the oxygen sensor by hand. Repeat for any of the other sensors that need removed.
Clean the threads of the oxygen sensor with a wire brush and apply a coat of copper anti-seize if the sensor is not being replaced. Inspect the new sensor to ensure it matches the old oxygen sensor and there is an anti-seize compound pre-applied to the threads. Thread the 18 mm tap into the oxygen sensor hole in the exhaust and rotate it clockwise to clean any old compound from the threads. Remove the tap and thread the oxygen sensor into place.
Install the oxygen sensor socket onto the oxygen sensor so the pig tail extends through the slotted opening. Tighten the oxygen sensor to 22 foot-pounds with a torque wrench. Remove the oxygen sensor socket and ratchet. Connect the oxygen sensor pigtail to the vehicle wiring harness and pull on the plastic connectors to ensure they are properly connected.
Lift the front of the truck off the jack stands with a floor jack. Remove the jack stands from under the truck and lower the truck to the ground. Clear any stored trouble codes if a faulty oxygen sensor was replaced.
Tips & Warnings
- Do not use excessive force to remove the oxygen sensor to avoid damaging the exhaust. Instead, apply heat to the area surrounding the oxygen sensor with a propane torch to help loosen the sensor.
- Alldata: 2003 Dodge RAM, Oxygen Sensor Service and Repair, Removal and Replacement
- edmunds.com: Dodge RAM 1500 Pickup