This procedure covers the removal and replacement of a universal catalytic converter on a 2018-2024 Toyota Camry with the 2.5L I4 engine, including exhaust component disconnection and oxygen sensor handling.

Warnings

Tools required

Parts

• Universal catalytic converter × 1 — Must meet EPA requirements for 2.5L I4
• Exhaust flange gasket × 2 — Use OEM specification
• Exhaust pipe adapter pipes (if needed) × 1 — Specific to universal cat installation
• Exhaust clamps × 2 — Band clamps for universal installation
• Anti-seize compound × 1 — High-temperature rated

Preparation

1. Park vehicle on level surface and allow exhaust system to cool completely (minimum 2 hours after last operation)
2. Disconnect negative battery terminal to prevent accidental oxygen sensor damage from electrical testing during work
3. Raise front of vehicle using floor jack and secure on jack stands positioned at manufacturer frame jack points
4. Apply penetrating oil to all exhaust flange bolts, oxygen sensor threads, and heat shield bolts. Allow to soak for 15-20 minutes
5. Inspect catalytic converter location and determine cut points for universal converter installation (typically 6 inches before and after converter body)

Procedure

1. 1

   Remove heat shields
   Locate and remove the exhaust heat shields covering the catalytic converter area. Remove bolts securing heat shields to underbody and exhaust components. Set shields aside for reinstallation. Note the position and orientation of each shield for proper reassembly.
   Torque spec

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

   Disconnect upstream oxygen sensor
   Locate the upstream (front) oxygen sensor in the exhaust manifold or front pipe before the catalytic converter. Disconnect the electrical connector by pressing the release tab. Using an oxygen sensor socket or 22mm wrench, carefully unthread the sensor counterclockwise. Work slowly to avoid breaking the sensor if it is seized. If sensor is being reused, protect threads and sensor tip from contamination.
   ⚠If oxygen sensor is seized, apply additional penetrating oil and use heat carefully with a propane torch on the bung only, avoiding the sensor body and wiring.
   Torque spec

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

   Disconnect downstream oxygen sensor
   Locate the downstream (rear) oxygen sensor after the catalytic converter. Disconnect the electrical connector. Using an oxygen sensor socket or 22mm wrench, remove the sensor counterclockwise. Store sensor in a clean location if reusing. The 2018-2024 Camry 2.5L typically has the downstream sensor on the outlet side of the converter or in the mid-pipe.
   Torque spec

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

   Support exhaust system
   Position a floor jack with a block of wood under the exhaust pipe downstream of the catalytic converter to support the weight of the exhaust system. Raise jack just enough to take tension off exhaust hangers but not to lift the vehicle. This prevents exhaust system from dropping when converter is cut out.
   ⚠Do not place jack directly under catalytic converter or areas to be cut. Support must be on solid pipe sections that will remain.
5. 5

   Disconnect front exhaust flange
   Locate the exhaust flange connection between the exhaust manifold front pipe and the catalytic converter inlet. Remove the two or three flange bolts or nuts securing this connection. Separate the flanges and remove the old gasket. If bolts are severely corroded, cut with a reciprocating saw rather than risk breaking exhaust studs.
   Torque spec

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

   Measure and mark cut points
   Measure the length of the universal catalytic converter including inlet and outlet pipes. Mark cut points on the existing exhaust system to accommodate the new converter, ensuring adequate straight pipe on each side for secure clamping or welding. Typical cut points are 6 inches before converter inlet flange and 6 inches after converter outlet on the OEM system. Verify clearance to fuel lines, brake lines, and body components.
   ℹ️Ensure cut locations provide straight pipe sections of at least 2-3 inches for proper clamp or adapter fitment.
7. 7

   Cut out old catalytic converter
   Using an exhaust pipe cutter or reciprocating saw with metal-cutting blade, carefully cut through the exhaust pipe at the marked locations. Make cuts as straight and perpendicular to the pipe as possible for better fitment of universal converter. Remove the old catalytic converter and any remaining exhaust sections. Wear safety glasses as metal particles will be generated.
   ⚠Keep cutting tools away from fuel lines, brake lines, and vehicle wiring. Verify tool clearance before making cuts.
8. 8

   Prepare pipe ends
   Use a wire brush or grinder to clean the cut ends of the remaining exhaust pipes. Remove rust, scale, and burrs. Ensure pipe ends are as round and straight as possible. If pipes are crushed or damaged, use pipe expanders or cut back further to sound pipe. Clean pipe ends will ensure proper seal with clamps and adapters.
9. 9

   Test fit universal catalytic converter
   Position the universal catalytic converter in place with inlet toward engine and outlet toward rear. Verify proper alignment and clearance to underbody, frame rails, fuel tank, and suspension components. The converter should have minimum 1 inch clearance to all heat-sensitive components. Adjust position as needed. Mark final position on pipes.
   ⚠Ensure catalytic converter heat shield or body has adequate clearance from fuel tank and lines. Minimum 3 inches clearance recommended.
10. 10

    Install adapter pipes if needed
    If the universal converter pipe diameter does not match the OEM exhaust pipe diameter, install reducer or expander adapter pipes. Slide adapters onto existing exhaust pipes with larger end toward the cut pipe ends. Position band clamps on adapters but do not fully tighten yet. Verify smooth internal transitions to minimize exhaust restriction.
11. 11

    Install universal catalytic converter
    Slide the universal catalytic converter into position, connecting inlet to the front exhaust pipe and outlet to the rear exhaust pipe or adapter. Position band clamps over all joints. Align converter for proper clearances verified in test fit. Ensure oxygen sensor bungs are positioned for easy sensor installation and connector routing.
12. 12

    Secure all exhaust clamps
    Starting from the front connection and working rearward, tighten all band clamps evenly using a socket wrench. Tighten clamps to manufacturer specifications (typically 40-50 ft-lb for band clamps, but follow clamp manufacturer instructions). Verify no gaps exist in joints. Check that exhaust system hangs level and maintains clearances to all components. Adjust as necessary before final tightening.
    ℹ️Tighten clamps progressively in multiple passes rather than fully tightening one at a time to ensure even compression and best seal.
13. 13

    Reinstall oxygen sensors
    Apply a thin coat of anti-seize compound to the threads only (not the tip) of both oxygen sensors. Thread upstream sensor into front bung and downstream sensor into rear bung by hand to avoid cross-threading. Tighten sensors to specification using oxygen sensor socket or 22mm wrench. Reconnect both oxygen sensor electrical connectors, ensuring connectors click securely and wiring is routed away from hot exhaust components.
    ⚠Do not apply anti-seize to sensor tip or allow contamination of the sensing element. Only apply to threads.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
14. 14

    Reinstall heat shields
    Position exhaust heat shields in their original locations over the catalytic converter and exhaust pipes. Install and tighten heat shield bolts to specification. Ensure shields do not contact or rattle against exhaust components. Heat shields must be properly installed to protect underbody components and reduce cabin heat.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
15. 15

    Final inspection and lower vehicle
    Perform final visual inspection of all connections, clamps, oxygen sensors, and clearances. Verify all tools and parts have been removed from under vehicle. Remove exhaust support jack. Reconnect negative battery terminal. Lower vehicle from jack stands carefully and remove stands.

Reassembly

1. Ensure all exhaust clamps are tightened to proper specification and connections are leak-free
2. Verify oxygen sensor connectors are fully seated and wiring is secured away from exhaust components
3. Confirm all heat shields are reinstalled and properly secured
4. Check that exhaust system maintains proper clearance to fuel tank, lines, suspension, and body components throughout full suspension travel

Verification

• Start engine and allow to idle. Listen for exhaust leaks at all connection points. A hissing sound indicates a leak that must be corrected
• Inspect all connections while engine is running for visible exhaust gases escaping (may appear as heat shimmer)
• Use OBD-II scanner to verify no oxygen sensor fault codes are present. Codes P0420, P0430, P0131-P0138 indicate sensor or converter issues
• Test drive vehicle for 10-15 minutes, then re-inspect all clamp connections for looseness or leaks. Retighten if necessary
• After 50-100 miles of driving, perform final inspection of clamp tightness and verify no exhaust leaks have developed
• Monitor check engine light. If illuminated, scan for fault codes related to catalytic converter efficiency or oxygen sensor function

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