Remove the Sensors

• 1). Locate the oxygen sensor or sensors you want to replace. Look between the exhaust manifold and the catalytic converter assembly. Most models have one threaded into or near the exhaust manifold and another one close to the catalytic converter. They are a cylindrical in shape and about the size of a spark plug with an electrical connector attached to it.
  
  
• 2). Start and warm up the engine for about four minutes. This will help detach the sensor from the exhaust system.
  
  
• 3). Detach the ground battery cable using a wrench. This is the cable with black insulation attached to the battery post with the minus sign next to it.
  
  
• 4). Raise the front of your vehicle using a floor jack and safely support it on two jack stands.
  
  
• 5). Remove the engine undercover using a wrench or ratchet and socket.
  
  
• 6). Unplug the HO2S's electrical connector.
  
  
• 7). Remove the sensor harness from the holding bracket by hand.
  
  
• 8). Unscrew the oxygen sensor using a ratchet and oxygen sensor socket. If the sensor seems firmly attached, do not force it loose or you may damage the mounting threads. Spray the sensor with penetrating oil following the instructions on the product's package to ease the sensor off the mounting surface.
  
  

Install the New Sensors

• 1). Cover the new sensor threads with anti-seize compound and start the sensor by hand to prevent damage to the threads.
  
  
• 2). Tighten the sensor using the ratchet and oxygen sensor socket.
  
  
• 3). Hook the sensor harness to the holding bracket by hand.
  
  
• 4). Plug the sensor electrical connector.
  
  
• 5). Remove the other sensor and install the new one, if necessary, following the same procedure starting with Step 5 of the previous section up to the previous step.
  
  
• 6). Replace the engine undercover using the wrench or ratchet and socket.
  
  
• 7). Lower the vehicle.
  
  
• 8). Attach the ground battery cable using the wrench.