Downpipe

This procedure covers the removal and replacement of the downpipe (front exhaust pipe) connecting the catalytic converter to the center exhaust section on a 2019-2024 Toyota RAV4 with the 2.5L I4 engine.

Warnings

Tools required

Parts

• Downpipe gasket (catalytic converter to downpipe) × 1 — Use OEM specification
• Downpipe gasket (downpipe to center pipe) × 1 — Use OEM specification
• Exhaust flange nuts (if corroded) × 4 — M10 x 1.25 flange nuts
• Heat shield (if damaged) × 1 — Use OEM specification

Preparation

1. Ensure engine and exhaust system are completely cold to the touch
2. Park vehicle on level surface and engage parking brake
3. Raise vehicle using floor jack and support securely on jack stands rated for vehicle weight
4. Remove engine splash shield or under covers if equipped using 10mm socket
5. Spray all exhaust flange nuts and O2 sensor with penetrating oil and allow to soak for 15-30 minutes

Procedure

1. 1

   Disconnect oxygen sensor
   Locate the oxygen sensor on the downpipe. Disconnect the electrical connector by pressing the release tab. Using an O2 sensor socket, carefully unthread the sensor counterclockwise. If sensor is being reused, inspect threads and apply anti-seize to threads only (not sensor tip) before reinstallation.
2. 2

   Remove heat shields
   Remove any heat shields covering the downpipe or catalytic converter connection points using a 10mm socket. There are typically 2-4 bolts securing the heat shield(s). Set shields and hardware aside for reinstallation.
3. 3

   Disconnect downpipe from catalytic converter
   Locate the flange connection between the catalytic converter and downpipe. Using a 14mm socket and breaker bar if necessary, remove the two flange bolts/nuts securing this connection. Support the downpipe weight to prevent it from falling when the last fastener is removed.
   ⚠Flange may be stuck due to carbon buildup. Use a pry bar gently if needed, but do not damage the catalytic converter flange surface.
4. 4

   Remove exhaust hanger support
   Locate the rubber exhaust hanger(s) supporting the downpipe or center pipe section. If there is a hanger bolt securing a bracket to the chassis, remove it using a 12mm socket. Otherwise, carefully pry the rubber hanger off its mounting hook using a pry bar.
5. 5

   Disconnect downpipe from center exhaust pipe
   Move to the rear flange connection where the downpipe connects to the center exhaust section. Using a 14mm socket, remove the two flange bolts/nuts at this connection. Keep track of any springs or spacers if present.
6. 6

   Remove downpipe assembly
   With all fasteners removed, carefully lower and remove the downpipe from the vehicle. Maneuver it past any suspension components or subframe members. Inspect the old gaskets and flange surfaces for damage.
7. 7

   Clean flange surfaces
   Using a wire brush and scraper, thoroughly clean both flange surfaces on the catalytic converter and center exhaust pipe. Remove all old gasket material, carbon deposits, and corrosion. Clean surfaces ensure proper sealing with new gaskets.
8. 8

   Install new downpipe with gaskets
   Position new gaskets on both flange connections. Carefully maneuver the new downpipe into position, aligning the flanges. Hand-start all flange bolts/nuts before tightening any of them. Apply anti-seize compound to exhaust flange bolt threads per specification.
9. 9

   Torque catalytic converter flange connection
   Starting with the catalytic converter to downpipe connection, torque the flange bolts in a cross pattern to ensure even clamping force and proper gasket compression. Verify the flange is fully seated.
10. 10

    Torque center pipe flange connection
    Torque the downpipe to center pipe flange bolts in a cross pattern. Ensure the pipes are properly aligned before final tightening to prevent stress on the exhaust system.
11. 11

    Reinstall exhaust hangers
    Reconnect the rubber exhaust hanger(s) to their mounting hooks. If a hanger bracket was removed, reinstall and torque the mounting bolt. Ensure the exhaust system hangs evenly without excessive stress on any connection point.
12. 12

    Install oxygen sensor
    Apply a small amount of anti-seize compound to the oxygen sensor threads only (avoid the sensor tip). Thread the sensor into the downpipe by hand until seated, then torque to specification using the O2 sensor socket. Reconnect the electrical connector until it clicks.
13. 13

    Reinstall heat shields
    Position heat shields back in their original locations and secure with the heat shield bolts. Torque to specification. Ensure shields do not contact any moving components or wiring.

Reassembly

1. Reinstall engine splash shields or under covers and torque fasteners to specification
2. Lower vehicle from jack stands carefully
3. Visually inspect all connections from underneath before starting engine

Verification

• Start engine and allow to idle. Listen for any exhaust leaks at flange connections - a ticking or hissing sound indicates a leak
• Check for visible exhaust smoke escaping from flange joints
• Rev engine to 2500-3000 RPM and verify no abnormal noises or leaks develop
• After initial test, re-check all flange bolt torque when exhaust has cooled
• Test drive vehicle and verify normal performance with no exhaust odor in cabin
• Check for diagnostic trouble codes related to oxygen sensor or exhaust system using OBD-II scanner

More procedures for this vehicle