Removal and installation of the exhaust system 4.0L (Discovery 3)

Special tool

HO2S Sensor Key 310-121 (LRT-19-014)

Removal

1. Disconnect the ground cable from the battery. For more information, refer to Specification.

2.

CAUTION: Never work on a vehicle supported solely by a jack. Always support the vehicle securely.

Raise and support the vehicle.

3. Remove the engine protection. For more information, refer to Engine Protection (76.10.50)

4. Remove the transmission crossmember. For more information, refer to Transmission Support Crossmember (76.10.09 or 76.10.92)

5. Release the left front HO2S sensor wiring harness. Disconnect the electrical connector.



6. Release the right front HO2S wiring harness. Disconnect the electrical connector.





7. Release the left rear HO2S wiring harness. Disconnect the electrical connector.

8. Release the right rear HO2S wiring harness. Disconnect the electrical connector.



9. Disconnect the left catalytic converter from the exhaust manifold. Remove and discard the 2 bolts.



10. Disconnect the right catalytic converter from the exhaust manifold. Remove and discard the 2 bolts.





11. Remove the exhaust system with assistance. Disconnect the 5 exhaust system hangers.



12.

NOTE: Do not perform further disassembly if the component is removed only for access.

Using the special tool, remove the 4 HO2S sensors from the catalytic converters.

Installation

1.

CAUTION: Avoid getting grease on the tip of the HO2S sensor.

Using the special tool, install the HO2S sensors onto the catalytic converters and tighten to 45 Nm.

• Clear the elements.
• Apply grease to the HO2S sensor threads.

2. Install the exhaust system with assistance. Secure the exhaust system hangers.

3. Connect the right catalytic converter to the exhaust manifold.

• Clear the elements.
• Tighten the new bolts to 22 Nm.

4.

CAUTION: Make sure that the distance (A) between the nearest surfaces of the left catalytic converter and the front propeller shaft is 25-30 mm.

Connect the left catalytic converter to the exhaust manifold.

• Clear the elements.
• Tighten the new bolts to 22 Nm.

5.

CAUTION: Ensure that the heated oxygen sensor wiring harness does not have bends greater than 180 degrees and does not touch the exhaust manifold or propeller shaft.

Connect the HO2S sensor electrical connectors. Secure the HO2S wiring harnesses.

6. Install the transmission crossmember. For more information, refer to Transmission Support Crossmember (76.10.09 or 76.10.92)

7. Install the engine protection. For more information, refer to Engine Protection (76.10.50)

8. Connect the ground cable to the battery. For more information, refer to Specification.