This procedure covers the replacement of the flex pipe section of the exhaust system on a 2019-2024 Toyota RAV4 with the 2.5L I4 gas engine.

Warnings

Tools required

Parts

• Flex pipe assembly × 1 — Use OEM specification
• Exhaust flange gasket × 2 — Use OEM specification
• Exhaust hardware kit (bolts/nuts) × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground and apply parking brake
2. Place wheel chocks behind rear wheels
3. Allow exhaust system to cool completely (minimum 1 hour after engine operation)
4. Raise front of vehicle and support securely on jack stands at manufacturer-recommended lift points
5. Spray all exhaust fasteners with penetrating oil and allow to soak for 30 minutes
6. Ensure adequate ventilation if working in enclosed space due to rust and debris

Procedure

1. 1

   Locate and inspect flex pipe
   From under the vehicle, locate the flex pipe section between the catalytic converter and mid-pipe. The flex pipe is typically positioned approximately 18-24 inches behind the engine block. Inspect the area for rust, cracks, or separation to confirm flex pipe failure.
2. 2

   Disconnect oxygen sensor
   Locate the downstream oxygen sensor near the flex pipe connection. Disconnect the electrical connector by pressing the release tab. Using a 22mm oxygen sensor socket, carefully remove the oxygen sensor from the exhaust pipe. Thread the sensor out completely and set aside in a safe location to prevent damage to the sensor tip.
   Torque spec

   O2 Sensor47 Nm (35 lb-ft)
3. 3

   Support exhaust system
   Position a jack stand or transmission jack under the mid-pipe section behind the flex pipe to support the weight of the rear exhaust system. Apply only enough support to take up the weight without lifting or stressing the system.
4. 4

   Remove front exhaust hanger
   Locate the rubber exhaust hanger supporting the front section near the flex pipe. If the hanger is attached with bolts, remove them. Otherwise, carefully pry the hanger loop off the mounting bracket using a pry bar. Take care not to tear the rubber hanger if it will be reused.
   Torque spec

   Hanger Bolts20 Nm (15 lb-ft)
5. 5

   Remove upstream flange connection
   Locate the exhaust flange connection between the catalytic converter and flex pipe (upstream side). Remove the two or three flange bolts using a socket and ratchet. If bolts are severely rusted, apply additional penetrating oil and allow time to soak. Once bolts are removed, separate the flange connection and remove the old gasket.
   ⚠If bolts break or studs strip, the manifold or catalytic converter may require stud extraction or helicoil repair before proceeding.
   Torque spec

   Flange Bolts45 Nm (33 lb-ft)
6. 6

   Remove downstream connection
   Move to the downstream side of the flex pipe where it connects to the mid-pipe. If equipped with a flange connection, remove the flange bolts and separate. If equipped with a clamp connection, loosen and remove the exhaust clamp bolts completely. Separate the connection and remove any old gaskets or seals.
   Torque spec

   Flange Bolts45 Nm (33 lb-ft)

   Exhaust Clamps55 Nm (41 lb-ft)
7. 7

   Remove flex pipe assembly
   With both connections separated, carefully maneuver the flex pipe assembly out from under the vehicle. The assembly may need to be rotated or angled to clear suspension components and subframe members. Lower the rear exhaust support slightly if needed for clearance.
8. 8

   Clean mating surfaces
   Using a wire brush, thoroughly clean all flange mating surfaces on both the catalytic converter outlet and mid-pipe inlet. Remove all old gasket material, rust, and carbon deposits to ensure proper sealing. Clean the oxygen sensor bung threads with a thread chaser or wire brush.
9. 9

   Install new flex pipe
   Position new exhaust gaskets on both upstream and downstream flange connections. Maneuver the new flex pipe assembly into position, ensuring the flex section is oriented correctly with adequate clearance from heat shields and chassis components. Start all flange bolts hand-tight before final torquing.
10. 10

    Torque exhaust connections
    Torque the upstream flange bolts connecting the flex pipe to the catalytic converter to specification in a cross-pattern to ensure even gasket compression. Then torque the downstream connection (flange bolts or clamp bolts) to specification. Verify all connections are secure and gaskets are properly seated.
    Torque spec

    Flange Bolts45 Nm (33 lb-ft)

    Exhaust Clamps55 Nm (41 lb-ft)
11. 11

    Reinstall exhaust hanger
    Reattach the rubber exhaust hanger to the mounting bracket. If equipped with hanger bolts, install and torque to specification. Ensure the exhaust system hangs at the proper height with adequate clearance from chassis and suspension components.
    Torque spec

    Hanger Bolts20 Nm (15 lb-ft)
12. 12

    Reinstall oxygen sensor
    Apply a thin coat of anti-seize compound to the oxygen sensor threads (avoid getting anti-seize on the sensor tip). Thread the sensor into the bung by hand initially, then torque to specification using the oxygen sensor socket. Reconnect the electrical connector until it clicks into place.
    ⚠Do not overtighten oxygen sensor as this can damage the threads or sensor. Use a torque wrench for proper installation.
    Torque spec

    O2 Sensor47 Nm (35 lb-ft)
13. 13

    Verify clearances
    Inspect the entire exhaust system to verify adequate clearance from heat shields, fuel lines, brake lines, and chassis components. Check that all hangers are properly seated and the system is not under stress or binding. Adjust hanger positions if necessary.

Reassembly

1. Remove jack stands and lower vehicle to ground
2. Double-check all fasteners are torqued to specification
3. Verify oxygen sensor electrical connector is fully engaged

Verification

• Start engine and allow to idle. Listen for exhaust leaks at both flange connections
• Use soapy water solution on connections to check for leak bubbles while engine is running
• Rev engine to 2500 RPM and verify no abnormal exhaust sounds or vibrations
• Check for check engine light or oxygen sensor codes after test drive
• Perform a 10-15 minute test drive and recheck all connections for leaks and proper torque after exhaust system heats and cools
• Visually inspect underneath for proper exhaust system alignment and clearances after test drive

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