This procedure covers the removal and replacement of the exhaust resonator on a 2016-2021 Honda Civic with the 1.5L turbocharged engine.

Warnings

Tools required

Parts

• Exhaust resonator assembly × 1 — Use OEM specification
• Exhaust clamp (if equipped) × 2 — Use OEM specification
• Exhaust flange gasket × 2 — Use OEM specification
• Rubber exhaust hangers (if damaged) × 2 — Use OEM specification

Preparation

1. Park vehicle on level ground and engage parking brake
2. Place wheel chocks behind rear wheels
3. Allow exhaust system to cool completely (minimum 2 hours after last operation)
4. Apply penetrating oil to all exhaust flange bolts and clamps that will be removed
5. Raise front of vehicle with floor jack and support securely on jack stands at manufacturer-specified jacking points
6. Verify vehicle stability before working underneath

Procedure

1. 1

   Locate resonator assembly
   Position yourself under the vehicle mid-section. The resonator is located between the catalytic converter and the muffler, typically in the center tunnel area. Identify the front and rear connection points (either flanged connections or clamp-style connections depending on model year).
2. 2

   Support resonator weight
   Use a jack stand or adjustable support to lightly support the weight of the resonator from below. This prevents the component from falling when disconnected and reduces stress on the rubber hangers during removal.
3. 3

   Disconnect front connection
   If equipped with flange bolts, remove the two bolts connecting the resonator to the mid-pipe or catalytic converter using a 14mm socket. If equipped with band clamps, loosen the clamp bolt(s) using a 14mm socket and slide the clamp back away from the joint. Note the orientation of any gaskets for reinstallation.
   Torque spec

   Flange Bolts45 Nm (33 lb-ft)

   Exhaust Clamps55 Nm (41 lb-ft)
4. 4

   Disconnect rear connection
   Remove the fasteners at the rear connection to the muffler inlet pipe using the same method as the front connection. For flange connections, remove the two bolts with a 14mm socket. For clamp connections, loosen and slide the clamp away from the joint.
   Torque spec

   Flange Bolts45 Nm (33 lb-ft)

   Exhaust Clamps55 Nm (41 lb-ft)
5. 5

   Remove from exhaust hangers
   The resonator is supported by 1-2 rubber hangers. Using a pry bar or exhaust hanger removal tool, compress and unhook the metal hanger hooks from the rubber isolators. Work carefully to avoid tearing the rubber. If hangers are severely deteriorated or cracked, replace them during reassembly.
6. 6

   Remove resonator assembly
   Lower the resonator assembly from the vehicle. The resonator may require slight rotation or angling to clear surrounding components and the vehicle body. Inspect all removed components including gaskets, clamps, and hangers for damage or excessive wear.
7. 7

   Clean mating surfaces
   Using a wire brush, clean the mating surfaces at both the front and rear connection points. Remove all old gasket material, carbon deposits, and corrosion. Clean surfaces ensure proper sealing and prevent exhaust leaks.
8. 8

   Install new resonator
   Position the new resonator assembly under the vehicle, aligning it with the exhaust hangers first. Insert the metal hanger hooks into the rubber isolators. Support the resonator at the proper height to align with front and rear connection points. Install new flange gaskets at both connections if using flanged joints.
9. 9

   Connect front joint
   Align the front connection and install new flange bolts or reposition the band clamp. For flange connections, start both bolts by hand to ensure proper thread engagement. Do not fully tighten at this stage to allow for final alignment adjustment.
   Torque spec

   Flange Bolts45 Nm (33 lb-ft)

   Exhaust Clamps55 Nm (41 lb-ft)
10. 10

    Connect rear joint
    Align the rear connection to the muffler inlet pipe and install flange bolts or reposition the band clamp. Start all fasteners by hand. Ensure the entire exhaust system alignment appears centered and is not contacting the body, frame, or suspension components.
    Torque spec

    Flange Bolts45 Nm (33 lb-ft)

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

    Final tightening sequence
    Using a torque wrench, tighten all connections to specification. For flange bolts, torque to 45 Nm (33 lb-ft) in a cross-pattern. For exhaust clamps, torque clamp bolts to 55 Nm (41 lb-ft). Verify the resonator hangs level and is not under stress or misalignment.
    Torque spec

    Flange Bolts45 Nm (33 lb-ft)

    Exhaust Clamps55 Nm (41 lb-ft)

Reassembly

1. Double-check all connection points are properly torqued
2. Verify exhaust system has adequate clearance from body, frame, fuel lines, and brake lines throughout its length
3. Ensure rubber hangers are fully seated and not torn or overstretched

Verification

• Lower vehicle from jack stands and remove support equipment
• Start engine and listen for exhaust leaks at both resonator connections (hissing or ticking sounds indicate leaks)
• With engine at idle, visually inspect all connections for visible exhaust gas escaping
• Take vehicle for a brief test drive and recheck all connections for leaks after thermal cycling
• Verify no rattles or vibrations from the exhaust system during acceleration and deceleration

More procedures for this vehicle