Exhaust Manifold

This procedure covers removal and installation of the exhaust manifold on the 2012-2017 Toyota Camry 2.5L I4 engine, including heat shield removal and oxygen sensor handling.

Warnings

Tools required

Parts

• Exhaust manifold gasket × 1 — Use OEM specification
• Exhaust manifold nuts (set of 5) × 1 — Use OEM specification
• Exhaust flange gasket × 1 — Use OEM specification
• Exhaust flange bolts/nuts × 1 — Use OEM specification
• Heat shield bolts (if damaged) × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cold to the touch
2. Disconnect negative battery cable and secure away from terminal
3. Raise vehicle and support securely on jack stands at all four corners
4. Place wheel chocks behind rear wheels
5. Apply penetrating oil to all exhaust manifold nuts, heat shield bolts, and exhaust flange bolts; allow to soak minimum 30 minutes
6. Remove engine cover by pulling upward on corners to release clips

Procedure

1. 1

   Remove air intake components
   Disconnect the mass airflow sensor electrical connector. Loosen the air intake duct clamp at the throttle body and remove the air intake assembly to improve access to the manifold area. Set aside in a clean area.
2. 2

   Disconnect oxygen sensor
   From underneath the vehicle, locate the upstream oxygen sensor on the exhaust manifold. Disconnect the electrical connector by pressing the release tab. Using an oxygen sensor socket or 22mm wrench, carefully unthread the oxygen sensor from the manifold. Work slowly to avoid damaging threads.
   ⚠If oxygen sensor is seized, apply heat with a torch while engine is cold to aid removal. Do not force or threads will strip.
3. 3

   Remove exhaust heat shield
   Remove the upper heat shield bolts securing the heat shield to the exhaust manifold. There are typically 3-4 bolts. Keep track of bolt locations as lengths may vary. Remove the heat shield and set aside.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
4. 4

   Disconnect exhaust pipe from manifold
   Working from underneath the vehicle, support the front exhaust pipe with a jack or hanger wire. Remove the two bolts/nuts securing the exhaust flange to the manifold. Separate the exhaust pipe from the manifold and allow it to hang supported. Remove and discard the old flange gasket.
   ℹ️Flange may be stuck due to carbon buildup. Tap gently with a rubber mallet to separate if needed.
   Torque spec

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

   Remove exhaust manifold support bracket
   Locate the support bracket connecting the exhaust manifold to the engine block. Remove the mounting bolts securing the bracket to both the manifold and block. Remove the bracket and set aside.
   Torque spec

   Mounting Bolts47 Nm (35 lb-ft)
6. 6

   Remove exhaust manifold nuts
   Working from the engine bay, identify all five exhaust manifold nuts securing the manifold to the cylinder head. Begin removal from the center (hottest) nut and work outward toward the coolest ends. This is the hot-to-cold sequence. Remove all nuts and washers, keeping them organized.
   ⚠If a stud begins to turn with the nut, stop immediately and apply penetrating oil. Allow to soak then use two wrenches to hold stud while removing nut.
   Torque spec

   Exhaust Manifold Nuts30 Nm (22 lb-ft)
7. 7

   Remove exhaust manifold
   Carefully pull the exhaust manifold away from the cylinder head. It may require gentle wiggling to break the gasket seal. Once free, maneuver the manifold out of the engine bay. Remove and discard the old manifold gasket from the cylinder head.
8. 8

   Clean mating surfaces
   Using a gasket scraper, carefully remove all old gasket material from the cylinder head mating surface. Take care not to gouge or scratch the aluminum surface. Use a wire brush to clean the exhaust manifold studs. Wipe surfaces clean with a lint-free cloth. Inspect the manifold for cracks, especially around the ports.
   ⚠Do not use power tools on aluminum cylinder head surface. Hand scraping only to avoid damage.
9. 9

   Install new exhaust manifold gasket
   Position the new exhaust manifold gasket onto the cylinder head studs. Ensure the gasket is oriented correctly with any markings facing outward. Verify all stud holes align properly with the gasket.
10. 10

    Install exhaust manifold
    Carefully position the exhaust manifold onto the studs and gasket. Ensure all five studs pass through their respective holes in the manifold. Apply a thin coat of anti-seize compound to the threads of each manifold nut. Hand-thread all five nuts onto the studs, ensuring none are cross-threaded.
11. 11

    Torque exhaust manifold nuts
    Using a torque wrench, tighten the exhaust manifold nuts in the correct sequence (consult service manual for pattern, typically center-out). Work from hot-to-cold, starting at the center and moving toward the ends. Torque all nuts to specification in at least two progressive passes, first to 15 Nm, then to final specification.
    ⚠Uneven or improper torque sequence can warp the manifold and cause exhaust leaks. Follow factory sequence precisely.
    Torque spec

    Exhaust Manifold Nuts30 Nm (22 lb-ft)
12. 12

    Install support bracket
    Position the exhaust manifold support bracket and install the mounting bolts finger-tight. Torque the bolts to specification, ensuring the bracket is properly seated against both the manifold and engine block.
    Torque spec

    Mounting Bolts47 Nm (35 lb-ft)
13. 13

    Connect exhaust pipe to manifold
    Install a new exhaust flange gasket between the manifold and front exhaust pipe. Align the exhaust pipe to the manifold flange. Apply anti-seize to the flange bolt threads and install the bolts/nuts finger-tight. Torque to specification following the proper sequence (typically diagonal pattern).
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)
14. 14

    Install oxygen sensor
    Apply a thin coating of anti-seize compound to the oxygen sensor threads, avoiding the sensor tip. Carefully thread the oxygen sensor into the exhaust manifold by hand to prevent cross-threading. Tighten to specification using an oxygen sensor socket. Reconnect the electrical connector and ensure it clicks into place.
    Torque spec

    O2 Sensor47 Nm (35 lb-ft)
15. 15

    Install heat shield and finalize
    Position the heat shield over the exhaust manifold. Install the heat shield bolts and torque to specification following the proper sequence. Reinstall the air intake assembly and tighten the clamp at the throttle body. Reconnect the mass airflow sensor connector. Reinstall the engine cover. Reconnect the negative battery cable.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Double-check all electrical connectors are fully seated and locked
2. Verify all fasteners have been torqued to specification
3. Ensure no tools or parts are left in the engine bay
4. Lower vehicle from jack stands carefully

Verification

• Start the engine and listen for exhaust leaks at the manifold and flange connections
• Allow engine to reach operating temperature and inspect all connections for leaks
• Check for exhaust odors in the cabin which would indicate a leak
• Verify no warning lights are illuminated on the dashboard
• Test drive the vehicle and confirm normal engine performance and no unusual exhaust noise

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