General information
1. When servicing the oxygen sensor, observe the following special precautions:
- Oxygen sensors have a permanently attached flexible wire and electrical connector that cannot be removed from the sensor. Damage or removal of the flexible wire or electrical connector will destroy the sensor.
- Keep grease, dirt, and other contaminants away from the electrical connector and sensor.
- Do not use any brand of cleaning solvent to clean the oxygen sensor.
- Do not drop the sensor and handle it with extreme care.
Replacement
Note. Since the sensor is installed in the exhaust manifold or catalytic converter, both of which shrink when cold, it can be very difficult to unscrew the oxygen sensor when the engine is cold. To avoid damage to the sensor that may result from this, start the engine and let it run for one to two minutes, then turn it off. Be careful not to get burned during the following procedure.
Models with a four-cylinder engine
Front oxygen sensor
Note. On 2003 and prior models, there are two front oxygen sensors, one for each three-way catalytic converter, which are an integral part of the respective exhaust manifold. The front oxygen sensors are located at the upper ends of the three-way catalytic converters and are accessible through the exhaust manifold heat shield. On 2004 and later models, there is one three-way catalytic converter and therefore only one front oxygen sensor is installed, which is also located at the upper end of the catalytic converter and can also be accessed through the exhaust manifold heat shield.
2. Disconnect the ground wire from the battery (see paragraph 1 of chapter 5).
3. Locate the front oxygen sensor in the opening on the exhaust manifold heat shield (pic. 9.3), then locate the sensor harness, trace it to the electrical connector, and disconnect the connector.
Pic. 9.3. On four-cylinder engines, the frequent oxygen sensor is located in the exhaust manifold and can be accessed through a hole in the heat shield (2004 variant shown with one front oxygen sensor)
4. Carefully unscrew the front oxygen sensor from the exhaust manifold. If you do not remove the exhaust manifold heat shield, a special socket socket must be used to unscrew the oxygen sensor (pic. 9.9).
5. Installation is carried out in the reverse order of removal. Apply a suitable lubricant to the threads of the oxygen sensor, then tighten it to the specified torque specified in Specifications at the beginning of this chapter.
Rear oxygen sensor
Note. On models 2001-2003. There are two rear oxygen sensors, one for each of the two three-way catalytic converters integral to the respective exhaust manifold. The rear sensors are located directly on the lower ends of the converters. 2004 and later models use a single three-way catalytic converter and therefore only have one rear sensor, which is located on the front exhaust pipe connecting the three-way converter to the rear converter.
6. Disconnect the ground wire from the battery (see paragraph 1 of chapter 5).
7. Raise the vehicle and place secure supports under it.
8. Locate the rear oxygen sensor in the front exhaust pipe, then locate the sensor harness, trace it to the electrical connector, and disconnect the connector.
9. Remove the oxygen sensor (pic. 9.9).
Pic. 9.9. After disconnecting the electrical connector of the rear oxygen sensor, carefully unscrew the sensor using the special socket (shown) or a large wrench (when there is insufficient space to work with a wrench, a special socket for oxygen sensors is convenient to use)
10. Installation is carried out in the reverse order of removal. Apply a suitable lubricant to the threads of the sensor, then tighten it to the specified torque specified in Specifications at the beginning of this chapter.
Models with V6 engine
Front oxygen sensors
Note. The front oxygen sensors are located on the exhaust manifolds, above the three-way catalytic converters.
11. Disconnect the ground wire from the battery (see paragraph 1 of chapter 5).
12. Disconnect the front oxygen sensor electrical connector (pic. 9.12, a, b).
Pic. 9.12, a. Front oxygen sensor (A) for the front cylinder head on the V6 engine is located on the front exhaust manifold. To find the electrical connector, trace the wiring to the connector (IN), and then disconnect the connector. Then unscrew the sensor from the manifold
Pic. 9.12, b. Front oxygen sensor (A) for the rear cylinder head on a VG engine is located on the rear exhaust manifold. To find the electrical connector, trace the wiring to the connector (IN), and then disconnect the connector. Then unscrew the sensor from the manifold
13. If you are replacing the front oxygen sensor for the rear exhaust manifold, raise the front of the vehicle and place secure supports under it.
14. Remove the oxygen sensor from the exhaust manifold.
15. Installation is performed in the reverse order of removal. Apply a suitable lubricant to the threads of the sensor, then tighten it to the specified torque specified in Specifications at the beginning of this chapter.
Rear oxygen sensor (And)
Note. On models 7999-2003. The rear oxygen sensor is located just behind the rear flange for the rear catalytic converter, just before the first muffler. 2004 and later models have two rear oxygen sensors. The rear sensor for the front exhaust manifold is located in the front exhaust pipe, which connects the front exhaust manifold to the Y-pipe, which in turn connects the front and rear exhaust manifolds to the center exhaust pipe. The rear oxygen sensor for the rear exhaust manifold is also located in this Y-pipe (there is no connecting pipe between the rear exhaust manifold and the center exhaust pipe).
16. Disconnect the ground wire from the battery (see paragraph 1 of chapter 5).
17. Raise the car and place secure supports under it.
18. Locate the rear oxygen sensor (pic. 9.18) and trace the sensor wiring to the appropriate electrical connector. On some models, access to the rear sensor connector will require removal of the rear seat and carpeting (see chapter 11).
Pic. 9.18. On models 1999-2003. with V6 engine rear oxygen sensor (A) located just behind the flange for the rear catalytic converter, directly in front of the first muffler. To replace the sensor, remove the rear seat and carpet, disconnect the electrical connector in the sensor wiring harness (IN), and then unscrew the two nuts (WITH) and remove the sensor
19. Remove the oxygen sensor.
20. Installation is carried out in the reverse order of removal. Apply a suitable lubricant to the threads of the sensor, then tighten it to the specified torque specified in Specifications at the beginning of this chapter.