Replace the California-specification catalytic converter assembly on a 2019-2024 Toyota RAV4 with 2.5L I4 FWD engine, including oxygen sensor transfer and exhaust system reconnection.

Warnings

Tools required

Parts

• California-spec catalytic converter assembly × 1 — Use OEM or CARB-compliant aftermarket
• Exhaust flange gasket (front) × 1 — Use OEM specification
• Exhaust flange gasket (rear) × 1 — Use OEM specification
• Exhaust flange nuts × 4 — M10x1.25 hex nuts

Preparation

1. Park vehicle on level ground and apply parking brake
2. Place wheel chocks behind rear wheels
3. Ensure exhaust system is completely cool to the touch
4. Raise front of vehicle and support securely on jack stands at manufacturer-specified lift points
5. Spray all exhaust flange bolts and oxygen sensor with penetrating oil and allow 15-20 minutes to penetrate
6. Visually inspect new catalytic converter to confirm it matches California specifications and includes CARB executive order label

Procedure

1. 1

   Remove heat shields
   Locate and remove the catalytic converter heat shields. There are typically 2-3 bolts securing each shield section. Remove all 10mm bolts securing the upper and lower heat shields. Set shields and hardware aside for reinstallation.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
2. 2

   Disconnect upstream oxygen sensor
   Locate the upstream (front) oxygen sensor on the exhaust manifold side of the catalytic converter. Disconnect the electrical connector by pressing the release tab. Using a 22mm oxygen sensor socket, carefully unthread the sensor counterclockwise. Remove sensor and inspect threads on both sensor and mounting boss.
   ⚠Oxygen sensors are fragile. Do not drop or strike the sensor tip. Contamination of the sensor element will cause it to fail.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
3. 3

   Disconnect downstream oxygen sensor
   Locate the downstream (rear) oxygen sensor on the outlet side of the catalytic converter. Disconnect the electrical connector. Using the 22mm oxygen sensor socket, remove the downstream sensor. Keep sensors organized and labeled to ensure proper reinstallation position.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
4. 4

   Remove front exhaust flange connection
   Locate the 2-bolt flange connecting the exhaust manifold to the catalytic converter inlet. Using a 14mm socket, remove both flange bolts. Support the catalytic converter weight with one hand or a jack stand while removing fasteners. Separate the flange connection and remove the old gasket.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
5. 5

   Remove rear exhaust flange connection
   Locate the 2-bolt flange connecting the catalytic converter outlet to the mid-pipe. Remove both 14mm flange bolts. If flange is seized, carefully apply leverage to separate. Do not damage the mid-pipe flange surface.
   Torque spec

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

   Disconnect exhaust hangers
   The catalytic converter is supported by rubber exhaust hangers. Locate all hanger connection points (typically 2-3 locations). Using an exhaust hanger tool or carefully by hand, pop the rubber isolators off their mounting studs. Work each hanger free without tearing the rubber.
   ⚠Support the weight of the catalytic converter assembly before releasing the final hanger. The assembly weighs approximately 20-30 lbs.
   Torque spec

   Hanger Bolts20 Nm (15 lb-ft)
7. 7

   Remove catalytic converter assembly
   With all connections released, carefully lower and remove the catalytic converter assembly from the vehicle. Maneuver around subframe members and brake lines. Inspect mounting points and flanges for damage or excessive corrosion.
8. 8

   Prepare mounting surfaces
   Using a wire brush, thoroughly clean both flange surfaces on the exhaust manifold outlet and mid-pipe inlet. Remove all old gasket material, rust, and carbon buildup. Clean oxygen sensor bungs in the new catalytic converter. Inspect all flange surfaces for warping or damage.
9. 9

   Install oxygen sensors in new catalytic converter
   Apply a thin coat of anti-seize compound to the threads of both oxygen sensors (avoid getting anti-seize on the sensor tips). Thread each sensor by hand into the correct bung location on the new catalytic converter. Upstream sensor goes in the front bung, downstream in the rear. Tighten to specification using the 22mm oxygen sensor socket and torque wrench.
   ⚠Never apply anti-seize to the sensor element or electrical connector. Only apply to the threaded portion.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
10. 10

    Position new catalytic converter
    Maneuver the new catalytic converter assembly into position under the vehicle. Align the inlet flange with the exhaust manifold outlet and the outlet flange with the mid-pipe. Reconnect exhaust hangers to their rubber isolators, ensuring proper routing and no contact with body panels or suspension components.
11. 11

    Install front flange connection
    Position a new gasket between the exhaust manifold and catalytic converter inlet flanges. Insert both flange bolts and start threads by hand. Apply anti-seize compound to the bolt threads. Tighten bolts evenly in a cross pattern to the specified torque.
    ℹ️Tighten flange bolts gradually in alternating pattern to ensure even gasket compression and prevent flange warping.
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)
12. 12

    Install rear flange connection
    Position a new gasket between the catalytic converter outlet and mid-pipe inlet flanges. Insert both flange bolts and start by hand. Apply anti-seize compound to threads. Tighten bolts evenly in a cross pattern to specification.
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)
13. 13

    Verify hanger alignment
    Check that all exhaust hangers are properly seated on their rubber isolators and that the system hangs at the correct height with proper clearance. Adjust hanger positions if necessary. Tighten any adjustable hanger bolts to specification.
    Torque spec

    Hanger Bolts20 Nm (15 lb-ft)
14. 14

    Connect oxygen sensor wiring
    Route oxygen sensor wiring properly to avoid contact with hot exhaust components or moving parts. Connect both upstream and downstream oxygen sensor electrical connectors, ensuring they click securely into place. Verify connector locks are fully engaged.
15. 15

    Reinstall heat shields
    Position heat shields over the catalytic converter in their original locations. Install all mounting bolts and tighten to specification. Ensure shields do not contact the catalytic converter body directly and have proper clearance for thermal expansion.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Verify all fasteners are tightened to proper torque specifications
2. Confirm all oxygen sensor connectors are properly connected and secured
3. Check that no tools or parts were left in the work area
4. Verify exhaust system has adequate clearance from fuel lines, brake lines, and body panels throughout suspension travel

Verification

• Lower vehicle to ground and remove jack stands
• Start engine and allow to idle. Listen for any exhaust leaks at flange connections
• Check for exhaust odors in cabin which would indicate a leak
• Verify check engine light does not illuminate and no oxygen sensor codes are present
• With engine at operating temperature, visually inspect all connections for signs of leakage (soot staining)
• Test drive vehicle to confirm normal operation and no exhaust drone or vibration
• After test drive, re-inspect all flange connections and hangers for proper seating
• Verify catalytic converter CARB label is visible for future inspections

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