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    Honda CRV/Odyssey 1995-2000 Repair Information

    Oxygen Sensor

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    OPERATION



    See Figure 1

    Click image to see an enlarged view

    Fig. Fig. 1: Heated Oxygen (HO2) Sensor output voltage vs. mixture ratio

    An Oxygen (O 2 ) Sensor is an input device used by the engine control computer to monitor the amount of oxygen in the exhaust gas stream. The information is used by the computer, along with other inputs, to fine-tune the air/fuel mixture so that the engine can run with the greatest efficiency in all conditions. The O 2 sensor sends this information to the Engine Control Module/Powertrain Control Module (ECM/PCM) in the form of a 100-900 millivolt (mV) reference signal. The signal is actually created by the O 2 sensor itself through chemical interactions between the sensor tip material (zirconium dioxide in almost all cases) and the oxygen levels in the exhaust gas stream and ambient atmosphere gas. At operating temperatures, approximately 1100°F (600°C), the element becomes a semiconductor. Essentially, through the differing levels of oxygen in the exhaust gas stream and in the surrounding atmosphere, the sensor creates a voltage signal that is directly and consistently related to the concentration of oxygen in the exhaust stream. Typically, a higher than normal amount of oxygen in the exhaust stream indicates that not all of the available oxygen was used in the combustion process, because there was not enough fuel (lean condition) present. Inversely, a lower than normal concentration of oxygen in the exhaust stream indicates that a large amount was used in the combustion process, because a larger than necessary amount of fuel was present (rich condition). Thus, the engine ECM/PCM can correct the amount of fuel introduced into the combustion chambers by controlling the fuel injector opening time.

    The ECM/PCM uses the HO 2 sensor output voltage as an indication of the oxygen content of the burnt exhaust gasses. Because the oxygen content directly affects the HO 2 sensor output, the signal voltage from the sensor to the ECM/PCM fluctuates constantly. This fluctuation is caused by interaction between the ECM/PCM and the HO 2 sensor, which follows a general pattern: detect, compare, compensate, detect, compare, compensate, etc. This means that when the ECM/PCM detects a lean signal from the HO 2 sensor, it compares the reading with known parameters stored within its memory. It calculates that there is too much oxygen present in the exhaust gases, so it compensates by adding more fuel to the air/fuel mixture. This, in turn, causes the HO 2 sensor to send a rich signal to the computer, which, then compares this new signal, and adjusts the air/fuel mixture again. This pattern constantly repeats itself: detect rich, compare, compensate lean, detect lean, compare, compensate rich, etc. Since the HO 2 sensor fluctuates between rich and lean, and because the lean limit for sensor output is 100 mV and the rich limit is 900 mV, the proper voltage signal from a normally functioning O 2 sensor consistently fluctuates between 100-300 and 700-900 mV.

    The sensor voltage may never quite reach 100 or 900 mV, but it should fluctuate from at least below 300 mV to above 700 mV, and the mid-point of the fluctuations should be centered around 500 mV.

    To improve O 2 sensor efficiency, newer O 2 sensors were designed with a built-in heating element, and were called Heated Oxygen (HO 2 ) Sensors. The heating element was incorporated into the sensor so that the sensor would reach optimal operating temperature quicker, meaning that the O 2 sensor output signal could be used by the engine control computer sooner and also stabilizes the sensor's output. Because the sensor reaches optimal temperature quicker, vehicles can enjoy improved driveability and fuel economy even before the engine reaches normal operating temperature.

    Beginning with model year 1996, the On-Board Diagnostics second generation (OBD-II), an updated system based on the former OBD-I became mandatory for passenger vehicles produced for sale in the United States. The OBD-II system used on the CRV and Odyssey models is also installed on vehicles sold in Canada. This system requires the use of two HO 2 sensors, the Primary Heated Oxygen (PHO 2 ) Sensor and the Secondary Heated Oxygen (SHO 2 ) Sensor. The PHO 2 sensor is located before the catalytic converter and performs the same functions as the HO 2 sensor found on vehicles equipped with a single sensor. The Secondary Heated Oxygen (SHO 2 ) Sensor is located after the catalytic converter and enables the ECM/PCM to monitor the PHO 2 sensor and catalytic converter efficiency. The SHO 2 sensor mounted in the exhaust system after the catalytic converter is not used to affect air/fuel mixture, it is used solely to monitor the catalytic converter and PHO 2 sensor efficiency.

    TESTING



    The best, and most accurate method to test the operation of an O


    WARNING
    When testing or servicing a Heated Oxygen (O 2 sensor is with the use of either an oscilloscope or a Diagnostic Scan Tool (DST), following their specific instructions for testing. It is possible, however, to test whether the O 2 sensor is functioning properly within general parameters using a Digital Volt-Ohmmeter (DVOM), also referred to as a Digital Multi-Meter (DMM). Newer DMM's are often designed to perform many advanced diagnostic functions. Some are constructed to be used as an oscilloscope. Two in-vehicle testing procedures, and one bench test procedure, will be provided for the common zirconium dioxide oxygen sensor. The first in-vehicle test makes use of a standard DVOM with a 10 megohms impedance, whereas the second in-vehicle test presented necessitates the usage of an advanced DMM with MIN/MAX/Average functions. Both of these in-vehicle test procedures are likely to set Diagnostic Trouble Codes (DTC's) in the engine control computer. Therefore, after testing, be sure to clear all DTC's before retesting the sensor, if necessary. 2) Sensor, the vehicle will need to be started and the engine warmed up to operating temperature in order to perform the necessary testing procedures or to easily remove the sensor from its threaded fitting. This will create a situation that requires working around a HOT exhaust system. The following is a list of precautions to consider during this service:



    Do not pierce any wires when testing a HO 2 sensor, as this can lead to wiring harness damage. Backprobe the connector, when necessary.
     
    While testing the sensor, be sure to keep out of the way of moving engine components, such as the cooling fan. Refrain from wearing loose clothing that may become tangled in moving engine components.
     
    Safety glasses must be worn at all times when working on or near the exhaust system. Older exhaust systems may be covered with loose rust particles that can fall off when disturbed. These particles are not only a nuisance, they can cause eye injuries.
     
    Be cautious when working on and around the hot exhaust system. Painful burns will result if skin is exposed to the exhaust system pipes or manifolds.
     
    The HO 2 sensor may be difficult to remove when the engine temperature is below 120°F (48°C). Excessive force may damage the threads in the exhaust pipe, therefore always start the engine and allow it to reach normal operating temperature prior to removal.
     
    Since HO 2 sensors are usually designed with a permanently attached wiring pigtail (this allows the wiring harness and sensor connectors to be positioned away from the hot exhaust system), it may be necessary to use a socket or wrench that is designed specifically for this purpose.
     

    CRV and Odyssey Model In-Vehicle Testing


    WARNING
    The four wire Heated Oxygen (HO2) Sensor have two separate circuits, the signal circuit and the heater circuit which must not be confused. Never apply voltage to the signal wiring of a HO2sensor, otherwise it may be damaged. Also, never connect an ohmmeter (or a DVOM set on the ohm function) to both of the signal wires of a HO2sensor at the same time, otherwise the sensor may be damaged.

    The color of the wires for the HO 2 sensor vary from model to model, however the positioning of the wires is consistent. The signal and heater connector circuit locations are identical on the CRV and the Odyssey models. With HO 2 sensor disconnected, hold the electrical multi-connector such that the locking tab is at the top, while facing the electrical connectors. The two top electrical connectors are the sensor terminals. The two bottom electrical connectors are the heater terminals. The two electrical connectors on the left side are the (+) positive part of the circuit and the two electrical connectors on the right side are the (-) negative part of the circuit.

    See Figure 2

    Click image to see an enlarged view

    Fig. Fig. 2: A Heated Oxygen Sensor has two separate electrical circuits. The sensor circuit, which measures the oxygen content of the exhaust and the heater circuit, used to stabilize the sensor

    Test 1 makes use of a standard DVOM with a 10 megohms impedance, whereas Test 2 necessitates the usage of an advanced Digital Multi-Meter (DMM) with MIN/MAX/Average functions or a sliding bar graph function. Both of these in-vehicle test procedures are likely to set Diagnostic Trouble Codes (DTC's) in the Engine Control Module/Powertrain Control Module (ECM/PCM). Therefore, after testing, be sure to clear all DTC's before retesting the sensor, if necessary. The Test 3 in-vehicle test is designed for the use of a scan tool or oscilloscope. The Test 4 Heating Circuit Test is designed to check the function of the heating circuit of the HO 2 sensor.

    The Honda models covered in this guide produced prior to 1996 use one Heated Oxygen (HO 2 ). Beginning with model year 1996, passenger vehicles sold in the United States were mandated to be On Board Diagnostic version II (OBD-II) compliant. The OBD-II equipped vehicles use two HO 2 sensors. The Primary Heated Oxygen (PHO 2 ) Sensor is located before the catalytic converter and is also referred to as Sensor 1 (S1). This is the sensor the ECM/PCM uses to monitor the oxygen content of the exhaust. The sensor located down stream from the catalytic converter is the Secondary Heated Oxygen (SHO 2 ). This sensor is also referred to as Sensor 2 (S2), and is used only to monitor the efficiency of the PHO 2 and the catalytic converter.

    The in-vehicle tests may be performed for the SHO 2 sensor, however under normal conditions, the SHO 2 sensor should not fluctuate like the PHO 2 ). Because the SHO 2 sensor is used only to monitor the efficiency of the PHO 2 sensor and the catalytic converter, if the HO 2 sensor exhibits a fluctuating signal, the catalytic converter is most likely defective.

    The following is a list of wire colors and the related circuit for the Heated Oxygen (HO 2 ) Sensor, Primary Heated Oxygen (PHO 2 ) Sensors, and Secondary Heated Oxygen (SHO 2 )Sensors used on CRV and Odyssey models.

    CRV Models- PHO 2



    + Signal Output: white, - Signal Ground: green/black
     
    + Heater Element Power: black/yellow, - Heater Element Ground: black/white
     

    CRV Models-



    SHO 2 :
     
    + Signal Output: white/red, - Signal Ground: green/white
     
    + Heater Element Power: black/white, - Heater Element Ground: black/white
     

    1995 Odyssey Models- HO 2



    + Signal Output: white/red, - Signal Ground: green/blue
     
    + Heater Element Power: yellow/black, - Heater Element Ground: orange/black
     

    1996-97 Odyssey Models- PHO 2



    + Signal Output: white/red, - Signal Ground: green/blue
     
    + Heater Element Power: black/yellow, - Heater Element Ground: orange/black
     

    1996-97 Odyssey Models-



    SHO 2 :
     
    + Signal Output: white/red, - Signal Ground: red/white
     
    + Heater Element Power: yellow/black, - Heater Element Ground: orange/black
     

    1998 Odyssey Models-PHO 2



    + Signal Output: white, - Signal Ground: green/black
     
    + Heater Element Power: black/yellow, - Heater Element Ground: black/white
     

    1998 Odyssey Models-



    SHO 2 :
     
    + Signal Output: white/red, - Signal Ground: green/black
     
    + Heater Element Power: yellow/black, - Heater Element Ground: orange/black
     

    1999-00 Odyssey Models- PHO 2



    + Signal Output: white, - Signal Ground: green/black
     
    + Heater Element Power: black/yellow, - Heater Element Ground: black/white
     

    1999-00 Odyssey Models-SHO 2



    + Signal Output: white/red, - Signal Ground: green/black
     
    + Heater Element Power: black/yellow, - Heater Element Ground: black/white
     

    TEST 1-DIGITAL VOLT-OHMMETER

    This test will not only verify proper sensor functioning, but is also designed to ensure the engine control computer and associated wiring is functioning properly as well.

    1. Start the engine and allow it to warm up to normal operating temperature.
    2.  

    If you are using the opening of the thermostat to gauge normal operating temperature, be forewarned: a defective thermostat can open too early and prevent the engine from reaching normal operating temperature. This can cause a slightly rich condition in the exhaust, which can throw the HO2sensor readings off slightly.

    1. Turn the ignition switch OFF , then locate the two signal wires of the HO 2 sensor pigtail connector.
    2.  
    3. Perform a visual inspection of the connector to ensure it is properly engaged and all terminals are straight, tight and free from corrosion or damage.
    4.  
    5. Disengage the sensor pigtail connector from the vehicle harness connector.
    6.  
    7. Using a DVOM set to read DC voltage, attach the positive lead to the Signal Output terminal of the sensor pigtail connector, and the DVOM negative lead to a good engine ground.
    8.  


    CAUTION
    While the engine is running, keep clear of all moving and hot components. Do not wear loose clothing. Otherwise severe personal injury or death may occur.

    1. Have an assistant start the engine and hold it at approximately 2000 rpm. Wait at least 1 minute before commencing with the test to allow the HO 2 sensor to sufficiently warm up.
    2.  
    3. Using a jumper wire, connect the Signal Output terminal of the vehicle harness connector to a good engine ground. This will fool the engine control computer into thinking it is receiving a lean signal from the HO 2 sensor, therefore, the computer will richen the air/fuel ratio. With the Signal Output terminal so grounded, the DVOM should register at least 800 mV, as the control computer adds additional fuel to the air/fuel ratio.
    4.  
    5. While observing the DVOM, disconnect the vehicle harness connector Signal Output jumper wire from the engine ground. Use the jumper wire to apply slightly less than 1 volt to the signal Output terminal of the vehicle harness connector. One method to do this is by grasping and squeezing the end of the jumper between your forefinger and thumb of one hand while touching the positive terminal of the battery post with your other hand. This allows your body to act as a resistor for the battery positive voltage, and fools the engine control computer into thinking it is receiving a rich signal. Or, use a mostly-drained AA battery by connecting the positive terminal of the AA battery to the jumper wire and the negative terminal of the battery to a good engine ground. (Another jumper wire may be necessary to do this.) The computer should lean the air/fuel mixture out. This lean mixture should register as 150 mV or less on the DVOM while connected to the Signal Output terminals of the HO 2 sensor.
    6.  
    7. If the DVOM did not register millivoltages as indicated, the problem may be either the sensor, the engine control computer or the associated wiring. Perform the following to determine which is the defective component:
      1. Remove the vehicle harness connector Signal Output jumper wire.
      2.  
      3. While observing the DVOM, artificially enrich the air/fuel charge using propane. The DVOM reading should register higher than normal millivoltages. (Normal voltage for an ideal air/fuel mixture is approximately 450-550 mV DC). Then, lean the air/fuel intake charger by either disconnecting one of the fuel injector wiring harness connectors (to prevent the injector from delivering fuel) or by detaching 1 or 2 vacuum lines (to add additional non-metered air into the engine). The DVOM should now register lower than normal millivoltages. If the DVOM functioned as indicated, the problem lies elsewhere in the fuel delivery and control system. If the DVOM readings were still unresponsive, the O 2 sensor is defective; replace the sensor and retest.
      4.  

    8.  

    Poor wire connections and/or ground circuits may shift a normal O2sensor's millivoltage readings up into the rich range or down into the lean range. It is a good idea to check the wire condition and continuity before replacing a component that will not fix the problem.

    1. Turn the engine OFF , remove the DVOM and all associated jumper wires. Reattach the vehicle harness connector to the sensor pigtail connector. If applicable, reattach the fuel injector wiring connector and/or the vacuum line(s).
    2.  
    3. Clear any DTCs present in the ECM/PCM memory, as necessary.
    4.  

    TEST 2-DIGITAL MULTI-METER

    This test method is a more straightforward Heated Oxygen (HO 2 ) Sensor test, and does not test the engine control computer's response to the HO 2 sensor signal. The use of a DMM with the MIN/MAX/Average function or sliding bar graph/wave function is necessary for this test. Don't forget that the Secondary Heated Oxygen (SHO 2 ) Sensor mounted after the catalytic converter (if equipped) will not fluctuate like the other Primary Heated Oxygen (PHO 2 ) Sensor will.

    1. Start the engine and allow it to warm up to normal operating temperature.
    2.  

    If using the opening of the thermostat to gauge normal operating temperature, be forewarned: a defective thermostat can open too early and prevent the engine from reaching normal operating temperature. This can cause a slightly rich condition in the exhaust, which can throw the HO2sensor readings off slightly.

    1. Turn the ignition switch OFF , then locate the HO 2 sensor pigtail connector.
    2.  
    3. Perform a visual inspection of the connector to ensure it is properly engaged and all terminals are straight, tight and free from corrosion or damage.
    4.  
    5. Backprobe the HO 2 sensor connector terminals. Attach the DMM positive test lead to the Signal Output terminal of the sensor pigtail connector. Attach the negative lead to either the Signal Ground terminal of the sensor pigtail or to a good, clean engine ground.
    6.  
    7. Activate the MIN/MAX/Average or sliding bar graph/wave function on the DMM.
    8.  


    CAUTION
    While the engine is running, keep clear of all moving and hot components. Do not wear loose clothing. Otherwise severe personal injury or death may occur.

    1. Have an assistant start the engine and wait a few minutes before commencing with the test to allow the HO 2 sensor to sufficiently warm up.
    2.  
    3. Read the minimum, maximum and average readings exhibited by the HO 2 sensor or observe the bar graph/wave form. The average reading for a properly functioning HO 2 sensor is be approximately 450-550 mV DC. The minimum and maximum readings should vary more than 300-600 mV. A typical HO 2 sensor can fluctuate from as low as 100 mV to as high as 900 mV; if the sensor range of fluctuation is not large enough, the sensor is defective. Also, if the fluctuation range is biased up or down in the scale. For example, if the fluctuation range is 400 mV to 900 mV the sensor is defective, because the readings are pushed up into the rich range (as long as the fuel delivery system is functioning properly). The same goes for a fluctuation range pushed down into the lean range. The mid-point of the fluctuation range should be around 400-500 mV. Finally, if the HO 2 sensor voltage fluctuates too slowly (usually the voltage wave should oscillate past the mid-way point of 500 mV several times per second) the sensor is defective. (When an O 2 sensor fluctuates too slowly, it is referred to as being "lazy".)
    4.  

    Poor wire connections and/or ground circuits may shift a normal HO2sensor's millivoltage readings up into the rich range or down into the lean range. It is a good idea to check the wire condition and continuity before replacing a component that will not fix the problem.

    1. Using the propane method, richen the air/fuel mixture and observe the DMM readings. The average HO 2 sensor output signal voltage should rise into the rich range.
    2.  
    3. Lean the air/fuel mixture by either disconnecting a fuel injector wiring harness connector or by disconnecting a vacuum line. The HO 2 sensor average output signal voltage should drop into the lean range.
    4.  
    5. If the HO 2 sensor did not react as indicated, the sensor is defective and should be replaced.
    6.  
    7. Turn the engine OFF , remove the DMM and all associated jumper wires. Reattach the vehicle harness connector to the sensor pigtail connector. If applicable, reattach the fuel injector wiring connector and/or the vacuum line(s).
    8.  
    9. Clear any DTC's present in the ECM/PCM memory, as necessary.
    10.  

    TEST 3-OSCILLOSCOPE

    This test is designed for the use of an oscilloscope to test the functioning of an Heated Oxygen (HO 2 Sensor.

    This test is only applicable for HO2and Primary Heated Oxygen (PHO2) Sensors mounted in the exhaust system before the catalytic converter.

    1. Start the engine and allow it to reach normal operating temperature.
    2.  
    3. Turn the engine OFF , and locate the HO 2 sensor connector. Backprobe the scope lead to the O 2 sensor connector Signal Output terminal. Refer to the scope manufacturer's instructions for more information on attaching the scope to the vehicle.
    4.  
    5. Turn the scope ON.
    6.  
    7. Set the oscilloscope amplitude to 200 mV per division, and the time to 1 second per division. Use the 1:1 setting of the probe, and be sure to connect the scope's ground lead to a good, clean engine ground. Set the signal function to automatic or internal triggering.
    8.  
    9. Start the engine and run it at 2000 rpm.
    10.  
    11. The oscilloscope should display a waveform, representative of the HO 2 sensor switching between lean (100-300 mV) and rich (700-900 mV). The sensor should switch between rich and lean, or lean and rich (crossing the mid-point of 500 mV) several times per second. In addition, the range of each wave should reach at least above 700 mV and below 300 mV. However, an occasional low peak is acceptable.
    12.  

    See Figure 3

    Click image to see an enlarged view

    Fig. Fig. 3: An oscilloscope wave form of a typical good HO2 sensor as it fluctuates from rich to lean

    1. Force the air/fuel mixture rich by introducing propane into the engine, then observe the oscilloscope readings. The fluctuating range of the HO 2 sensor should climb into the rich range.
    2.  
    3. Lean the air/fuel mixture out by either detaching a vacuum line or by disengaging one of the fuel injector's wiring connectors. Watch the scope readings; the HO 2 sensor waveform should drop toward the lean range.
    4.  
    5. If the HO 2 sensor's wave form does not fluctuate adequately, is not centered around 500 mV during normal engine operation, does not climb toward the rich range when propane is added to the engine, or does not drop toward the lean range when a vacuum hose or fuel injector connector is detached, the sensor is defective.
    6.  
    7. Reattach the fuel injector connector or vacuum hose.
    8.  
    9. Disconnect the oscilloscope from the vehicle.
    10.  

    TEST 4-HEATING CIRCUIT TEST

    The heating circuit in a Heated Oxygen (HO 2 ) Sensor is designed heat and stabilize the sensor quicker than a non-heated sensor. This provides an advantage of increased engine driveability and fuel economy while the engine temperature is still below normal operating temperature, because the fuel management system can enter closed loop operation (more efficient than open loop operation) sooner.

    Therefore, if the heating element goes bad, the HO 2 sensor may still function properly once the sensor warms up to its normal temperature. This will take longer than normal and may cause mild driveability-related problems while the engine has not reached normal operating temperature.

    If the heating element is found to be defective, replace the HO 2 sensor.

    1. Locate the O 2 sensor pigtail connector.
    2.  

    See Figure 4

    Click image to see an enlarged view

    Fig. Fig. 4: The heating circuit of the O2 sensor can be tested with a DMM set to measure resistance

    1. Perform a visual inspection of the connector to ensure it is properly engaged and all terminals are straight, tight and free from corrosion or damage.
    2.  
    3. Disengage the sensor pigtail connector from the vehicle harness connector.
    4.  
    5. Using a DVOM set to read resistance (ohms), attach 1 DVOM test lead to the Heater Element Power terminal, and the other lead to the Heater Element Ground terminal, of the sensor pigtail connector, then observe the resistance readings.
      1. If there is no continuity between the Heater Element Power and Heater Element Ground terminals, the sensor is defective. Replace it with a new one and retest.
      2.  
      3. If there is continuity between the 2 terminals, but the resistance is less than 10 ohms or greater than 40 ohms, the sensor is defective. Replace it with a new one and retest.
      4.  

    6.  
    7. Turn the engine OFF , remove the DVOM and all associated jumper wires. Reattach the vehicle harness connector to the sensor pigtail connector.
    8.  
    9. Clear any DTC's present in the ECM/PCM memory, as necessary.
    10.  

    REMOVAL & INSTALLATION




    WARNING
    The sensors use a pigtail and connector. This pigtail should not be removed from the sensor. Damage or removal of the pigtail or connector could affect proper operation of the oxygen sensor. Keep the electrical connector and louvered end of the sensor clean and free of grease. NEVER use cleaning solvents of any type on the sensor! The sensor may be difficult to remove when the engine temperature is below 120°F (48°C). Excessive removal force may damage the threads in the exhaust manifold or pipe; follow the removal procedure carefully.

    1. Make sure the ignition is OFF , then disconnect the negative battery cable.
    2.  
    3. Raise and safely support the vehicle.
    4.  
    5. Locate the oxygen sensor. It protrudes from the exhaust pipe (it looks somewhat like a spark plug).
    6.  
    7. Unplug the sensor electrical connector.
    8.  

    See Figures 5, 6 and 7

    Click image to see an enlarged view

    Fig. Fig. 5: The Heated Oxygen (HO2) Sensor threads into the exhaust system. Always disconnect the sensor pigtail before attempting removal



    Click image to see an enlarged view

    Fig. Fig. 6: A deep well socket with a slot for the pig tail wire is one type of tool used for removal of a Heated Oxygen (HO2) Sensor



    Click image to see an enlarged view

    Fig. Fig. 7: Coat only the threads of the Heated Oxygen (HO2) Sensor with an anti-seize compound

    There are special wrenches, either socket or open-end available from reputable retail outlets for removing the oxygen sensor. These tools make the job much easier and often prevent unnecessary damage.

    1. Carefully unscrew the sensor counterclockwise, then remove the oxygen sensor from the manifold or pipe.
    2.  

    To install:
    1. During and after the removal, be very careful to protect the tip of the sensor if it is to be reused. Do not let it to come in contact with fluids or dirt. Do not clean it or wash it.
    2.  
    3. Apply a light coat of anti-seize compound to the sensor threads but DO NOT allow any to get on the tip of the sensor.
    4.  
    5. Install the sensor into the exhaust pipe.
    6.  
    7. Attach the electrical connector and ensure a clean, tight connection.
    8.  
    9. Carefully lower the vehicle.
    10.  
    11. Connect the negative battery cable and enter the radio security code.
    12.  

     
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