This procedure covers the removal and replacement of the knock sensor on a 2019-2024 Toyota RAV4 with the 2.5L I4 gas engine, including access via intake manifold removal.

Warnings

Tools required

Parts

• Knock sensor × 1 — Use OEM specification
• Intake manifold gasket (if damaged) × 1 — Use OEM specification

Fluids

• Toyota Super Long Life Coolant (Pink) — 0.5 qt

Preparation

1. Ensure engine is completely cool to the touch
2. Disconnect negative battery terminal and wait 90 seconds
3. Remove engine cover by pulling upward on the four corner clips
4. Relieve any residual fuel system pressure
5. Position drain pan under vehicle to catch any coolant spillage
6. Take reference photos of vacuum lines, electrical connections, and hose routing

Procedure

1. 1

   Drain coolant partially
   Open the radiator drain valve or remove the lower radiator hose to drain approximately 2 quarts of coolant into a drain pan. This prevents coolant loss when disconnecting the throttle body coolant hoses. Close the drain valve once sufficient coolant is removed.
2. 2

   Remove air intake components
   Disconnect the mass airflow sensor electrical connector. Loosen the air intake hose clamp at the throttle body. Remove the air filter housing mounting bolts and disconnect any breather hoses. Remove the entire air intake assembly from the engine bay to provide access to the intake manifold.
3. 3

   Disconnect throttle body connections
   Disconnect the throttle body electrical connector by pressing the release tab. Disconnect the two coolant hoses from the throttle body using pliers to compress the spring clamps and slide them back. Have shop towels ready to catch coolant spillage. Cap or plug the coolant hoses to minimize further drainage.
   ⚠Coolant will drain from hoses when disconnected. Have shop towels and drain pan positioned to catch spillage.
4. 4

   Remove vacuum lines and PCV hoses
   Disconnect the brake booster vacuum line from the intake manifold by pulling the quick-disconnect fitting. Disconnect the PCV hose from the valve cover and intake manifold. Remove any additional vacuum lines or breather hoses connected to the intake manifold, noting their positions for reassembly.
5. 5

   Disconnect fuel injector harness
   Locate the fuel injector harness connector on the passenger side of the engine. Press the release tab and disconnect the main injector harness connector. Unclip any harness retaining clips from the intake manifold to allow the wiring to be moved aside.
6. 6

   Remove intake manifold support brackets
   Remove the intake manifold support bracket bolts on both sides of the manifold using a 12mm or 14mm socket. These brackets connect the intake manifold to the cylinder head and engine block. Set brackets and hardware aside in an organized manner.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
7. 7

   Remove intake manifold mounting bolts
   Remove the six intake manifold mounting bolts in a crisscross pattern starting from the outside and working inward. Use a 10mm socket with extensions as needed to reach all bolts. Once all bolts are removed, carefully lift the intake manifold away from the cylinder head. Inspect the gasket condition.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
8. 8

   Access and disconnect knock sensor
   With the intake manifold removed, locate the knock sensor on the front of the engine block between cylinders 2 and 3. It will have a single wire connector. Press the connector release tab and carefully disconnect the electrical connector from the knock sensor.
9. 9

   Remove knock sensor
   Using a 12mm deep socket with an extension, carefully remove the knock sensor bolt. Turn counterclockwise to loosen. Once the bolt is removed, carefully extract the knock sensor from the engine block. Note the orientation of the sensor for installation reference.
   ℹ️The knock sensor may be tight due to corrosion. Do not use excessive force that could damage the threads in the engine block.
10. 10

    Clean mounting surface
    Clean the knock sensor mounting surface on the engine block using a small wire brush and shop towel. Remove any corrosion, old sealant residue, or debris. Ensure the threaded hole is clean and free of obstructions. The mounting surface must be clean and flat for proper sensor operation.
11. 11

    Install new knock sensor
    Insert the new knock sensor into the mounting hole, ensuring it is oriented correctly and seats flush against the engine block. Thread the sensor bolt by hand initially to prevent cross-threading. Using a torque wrench and 12mm socket, tighten the knock sensor to exactly 20 Nm (15 lb-ft). This torque specification is critical for proper sensor function.
    ⚠Torque specification is critical. Over-torquing can damage the sensor or engine block; under-torquing will cause erratic knock detection and poor engine performance.
    Torque spec

    Knock Sensor20 Nm (15 lb-ft)
12. 12

    Reconnect knock sensor connector
    Connect the electrical connector to the knock sensor, ensuring it clicks securely into place. Verify the connector is fully seated and the locking tab is engaged. Route the wiring away from heat sources and moving components.
13. 13

    Reinstall intake manifold
    Inspect the intake manifold gasket and replace if damaged or deteriorated. Position the gasket on the cylinder head, then carefully lower the intake manifold into place, aligning all bolt holes. Install all six mounting bolts hand-tight first, then torque in a crisscross pattern from the center outward to the specified value.
    Torque spec

    Mounting Bolts27 Nm (20 lb-ft)
14. 14

    Reinstall support brackets and connections
    Reinstall the intake manifold support brackets and torque the mounting bolts to specification. Reconnect the fuel injector harness connector until it clicks. Reconnect all vacuum lines, PCV hoses, and breather hoses to their original positions using reference photos.
    Torque spec

    Mounting Bolts27 Nm (20 lb-ft)
15. 15

    Reconnect throttle body and air intake
    Reconnect the two coolant hoses to the throttle body and position the spring clamps properly. Reconnect the throttle body electrical connector. Reinstall the air intake assembly, tighten the intake hose clamp at the throttle body, reconnect the MAF sensor, and secure all mounting bolts and breather hoses.

Reassembly

1. Refill the cooling system with Toyota Super Long Life Coolant (Pink) to the proper level
2. Reconnect the negative battery terminal
3. Reinstall the engine cover by pressing down on all four clips until they seat properly
4. Start the engine and check for coolant leaks at the throttle body connections
5. Allow engine to reach operating temperature and verify cooling system is properly bled of air
6. Check for vacuum leaks by listening for hissing sounds around the intake manifold

Verification

• Use an OBD-II scanner to verify no knock sensor codes (P0325, P0326, P0327, P0328) are present
• Clear any existing diagnostic trouble codes and perform a test drive
• Monitor knock sensor data using live data on the scanner during light acceleration to verify proper signal
• Verify engine runs smoothly without hesitation, pinging, or performance issues
• Recheck all coolant hose connections and fluid levels after test drive
• Confirm no vacuum leaks are present and idle is smooth and stable

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