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Toyota Camry 2002-2006: How to Replace Knock Sensor

Your engine's knock sensor records engine noise (known as "knock") and sends these signals to the engine computer to pull ignition advance out of the cylinders to avoid further pinging, or knock, which can damage the engine. This article will show you how to replace your old knock sensor and get your ride running smoothly again.

By Brett Foote - August 5, 2015

This article applies to the 5th generation Toyota Camry (2002-2006).

Faulty knock sensors usually, but not always, trigger a check engine light. This isn't always a sure diagnosis however, because cheap gasoline can sometimes cause detonation and trigger a faulty code. If you fill up with good gas and still have trouble, it might be the knock sensor. Some other symptoms include thumping noises coming from the engine that get louder over time, misfires when starting the engine, strong exhaust smells, shaking or vibrating, hesitating, jerking, or increased fuel consumption. While you can reach the knock sensors under the hood by removing a number of parts, it's actually easier to get to underneath your Camry. This article will detail the steps involved in completing the job using this method.

Materials Needed

  • Ratchet
  • 27mm deep socket
  • Floor jack
  • Jack stands
  • 10, 12, and 14mm sockets
  • Adjustable wrench

Step 1 – Prepare the car

Disconnect the negative (black) battery terminal before beginning. Use a floor jack to lift up the front of the car and suspend it on jack stands.

Figure 1. Jack up the front of the car and place it on jack stands.

(Related Article: How to Jack Up Your Car - CamryForums.com)

Step 2 – Remove the knock sensor

Remove the metal bracket brace that connects the intake manifold to the transmission by removing the 12mm and 14mm bolts holding it in place. Remove the wiring harness from the sensor. Use a 27mm deep socket and ratchet to remove the knock sensor. These can sometimes be very difficult to remove, so if needed, you can set the ratchet in place and grab it through the top of the engine bay to get better leverage. Once loose, remove the old knock sensor.

Figure 2. Remove the old knock sensor.

Step 3 – Install new knock sensor

Install the new knock sensor and use the 27mm socket and wrench to tighten it in place. Again, tightening from the top of the engine bay makes gaining necessary leverage a lot easier. Re-install the metal bracket brace, and replace as well as re-tighten the 12mm and 14mm bolts holding it in place. Connect the wiring harness to the new knock sensor. Reconnect the negative battery terminal. Lift the car off the jack stands and set on the ground. Start the car and make sure everything is running smoothly.

Figure 3. Once installation is finished, test to ensure everything is working properly.

Featured Video: Replacing Knock Sensor on Toyota Camry

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