Resonator

This procedure covers the removal and replacement of the exhaust resonator on the 2018-2024 Honda Accord 1.5L Turbo, which is located mid-pipe in the exhaust system between the catalytic converter and rear muffler.

Warnings

Tools required

Parts

• Exhaust resonator assembly × 1 — 18310-6A0-A00 or equivalent
• Exhaust gasket (flange to catalytic converter) × 1 — Use OEM specification
• Exhaust gasket (flange to muffler) × 1 — Use OEM specification
• Rubber exhaust hangers (if damaged) × 2 — Use OEM specification

Preparation

1. Ensure the exhaust system has cooled completely (minimum 1 hour after engine shutdown)
2. Park vehicle on level ground and engage parking brake
3. Raise vehicle using lift or floor jack and support securely on jack stands at manufacturer-specified lift points
4. Verify vehicle is stable before working underneath
5. Spray all exhaust flange bolts and hanger bolts with penetrating oil and allow to soak for 10-15 minutes

Procedure

1. 1

   Locate and inspect resonator assembly
   Position yourself under the vehicle center section. The resonator is located approximately midway along the exhaust system, between the catalytic converter (forward) and the rear muffler (rearward). Inspect the resonator flanges, hangers, and connecting pipes for damage or excessive corrosion. Note the orientation of any clamps or hardware for reassembly.
2. 2

   Support the exhaust system
   Place a jack stand or suitable support under the muffler section to prevent the rear exhaust from dropping when the resonator is disconnected. Ensure the support is positioned to avoid damage to exhaust components.
3. 3

   Remove forward flange connection
   Locate the flange connection between the resonator inlet and the catalytic converter outlet. Remove the two flange bolts using a 14mm socket. If bolts are seized, apply additional penetrating oil and use controlled force to avoid breaking studs. Separate the flange connection carefully and remove the old gasket.
   Torque spec

   Flange Bolts45 Nm (33 lb-ft)
4. 4

   Remove rear flange connection
   Locate the flange connection between the resonator outlet and the muffler inlet pipe. Remove the two flange bolts using a 14mm socket. Carefully separate the flange and remove the old gasket. Inspect both flange surfaces for damage or warping.
   Torque spec

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

   Disconnect exhaust hangers
   The resonator is supported by rubber hangers attached to the vehicle body. Locate the rubber hangers on both sides of the resonator assembly. Use an exhaust hanger removal tool or pry bar to carefully work the rubber hangers off their mounting points. Avoid tearing the rubber if hangers are to be reused. Note the exact position of hangers for reinstallation.
   ⚠The resonator assembly will become loose once hangers are removed. Ensure adequate support is in place.
6. 6

   Remove resonator assembly
   With all connections and hangers disconnected, carefully lower and remove the resonator assembly from under the vehicle. Maneuver carefully to avoid contact with surrounding components or vehicle body. Inspect the old resonator for damage, rust perforation, or internal failure.
7. 7

   Clean flange surfaces
   Use a wire brush to thoroughly clean both the catalytic converter outlet flange and the muffler inlet flange. Remove all old gasket material, carbon deposits, and corrosion. Ensure flange surfaces are flat and smooth to prevent exhaust leaks. Inspect flange studs for damage or excessive corrosion.
8. 8

   Inspect and prepare new resonator
   Unpack the new resonator assembly and verify it matches the original part. Confirm the inlet and outlet diameters, overall length, and hanger positions are correct. Install new exhaust gaskets on both flanges with the smooth side facing the sealing surface.
9. 9

   Position new resonator
   Carefully lift the new resonator into position under the vehicle. Align the inlet flange with the catalytic converter outlet and the outlet flange with the muffler inlet. Position the rubber hangers near their mounting points but do not fully install yet to allow for alignment adjustment.
10. 10

    Install flange connections
    Install new flange bolts at both the forward (catalytic converter) and rear (muffler) connections. Hand-tighten all four bolts initially to allow for final alignment adjustment. Ensure gaskets remain properly seated during installation.
    Torque spec

    Flange Bolts45 Nm (33 lb-ft)
11. 11

    Install exhaust hangers
    With the resonator properly aligned, work the rubber hangers onto their body mounting points using an exhaust hanger tool or pry bar. Ensure hangers are fully seated on the mounting pins and that the resonator hangs naturally without binding or stress.
12. 12

    Torque flange bolts
    Using a torque wrench and 14mm socket, torque all four flange bolts (two forward, two rear) to 45.0 Nm (33.0 lb-ft) in a cross-pattern. Start with the forward flange, then proceed to the rear flange. Verify the resonator is properly aligned and centered in the vehicle tunnel with adequate clearance from the underbody, fuel tank, and suspension components.
    Torque spec

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

    Remove exhaust support
    Carefully remove the support from under the muffler section. Verify the entire exhaust system hangs properly on all rubber mounts without sagging or misalignment. Check for adequate clearance throughout the exhaust run.

Reassembly

1. Verify all flange bolts are torqued to specification and properly seated
2. Confirm all rubber exhaust hangers are fully engaged on their mounting points
3. Inspect the entire exhaust system for proper alignment and clearance from body, suspension, and fuel system components
4. Lower vehicle from jack stands carefully and remove supports

Verification

• Start the engine and listen for exhaust leaks at both flange connections. A hissing sound indicates a leak requiring re-torquing or gasket replacement
• With the engine running, inspect under the vehicle for visible exhaust gas escaping from connections
• Rev the engine to 2500-3000 RPM and verify no abnormal exhaust noise, vibration, or contact with vehicle components
• Take a short test drive and verify normal exhaust tone and no rattling or contact sounds during acceleration, deceleration, and over bumps
• After test drive, re-inspect flange connections while exhaust is hot for any signs of leakage or loosening

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