Resonator

Remove and replace the exhaust resonator on a 2009 Aston Martin DB9 6.0L V12, including exhaust section disconnection and hanger removal.

Warnings

Tools required

Parts

• Resonator assembly × 1 — Use OEM specification
• Exhaust clamp kit (if reusing clamps show wear) × 1 — Use OEM specification
• Exhaust gaskets (flange-type, if applicable) × 2 — Use OEM specification

Preparation

1. Ensure engine and exhaust system are completely cold to the touch (minimum 2-3 hours after last operation).
2. Raise vehicle on lift or securely support on jack stands at manufacturer-specified lift points. Ensure adequate working clearance underneath.
3. Inspect exhaust system to identify resonator location and confirm routing. The DB9 V12 typically has resonators in the mid-pipe section after the catalytic converters.
4. Apply penetrating oil to all exhaust clamp bolts, flange nuts, and hanger mounting points. Allow 15-20 minutes soak time.
5. Verify replacement resonator matches OEM configuration and fitment before beginning disassembly.

Procedure

1. 1

   Support exhaust system
   Position a transmission jack or suitable support under the resonator section to support the weight of the exhaust components. Adjust height to take load without putting tension on hangers or clamps. The resonator assembly and connected pipe sections are heavy and will drop when disconnected.
2. 2

   Disconnect oxygen sensors (if equipped on resonator section)
   Locate oxygen sensors mounted in or near the resonator section. Disconnect electrical connectors by pressing release tabs and pulling straight back. Oxygen sensors on the DB9 V12 are generally located at or near the catalytic converters, not on the resonator/mid-pipe section, so this step may not apply. If any sensor is present on the section being removed, disconnect its electrical connector; if the sensor itself must be removed, use an oxygen sensor socket of the correct size (verify in factory service data) and turn counterclockwise (right-hand thread). Mark sensor locations if multiple sensors are present to ensure correct reinstallation position. Note: If sensors must be removed from the resonator section, use an oxygen sensor socket (commonly 22mm) and turn counterclockwise. Note that on most DB9 configurations the O2 sensors are located at/near the catalytic converters upstream, not on the resonator section — verify presence before removing.
   Torque spec

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

   Remove forward exhaust connection
   Locate the clamp or flange connection between the resonator inlet and the forward exhaust section (typically after catalytic converters). If clamped, remove the clamp bolts using an appropriate socket. If flanged, remove the flange nuts. Verify the exact connection type and fastener count on this vehicle before removal. Separate the joint by pulling rearward on the resonator section. The joint may require gentle twisting or prying with a pry bar if corroded.
4. 4

   Remove rear exhaust connection
   Locate the clamp or flange connection between the resonator outlet and the rear exhaust section (muffler inlet pipes). Remove the clamp bolts or flange nuts as applicable — verify the exact connection type and fastener count on this vehicle before removal. Gently separate the joint. You may need to lower or shift the support jack slightly to provide access or relieve binding.
5. 5

   Remove exhaust hanger mounts
   Identify rubber exhaust hangers supporting the resonator section. The DB9 uses rubber isolator hangers on the mid-pipe section — verify the exact count and location on this vehicle before removal. Use an exhaust hanger removal tool or carefully pry the rubber hangers off their mounting studs using a pry bar. Work around the perimeter of each hanger to stretch it off the stud—avoid cutting or tearing the rubber if hangers are to be reused.
   Torque spec

   Hanger Bolts27 Nm (20 lb-ft)
6. 6

   Remove resonator assembly
   With all connections and hangers disconnected, carefully lower the resonator assembly on the support jack. Guide it down and out from under the vehicle. Have an assistant help control the component as it is heavy and awkward. Inspect mounting points and surrounding exhaust sections for damage or excessive corrosion.
7. 7

   Prepare mating surfaces
   Clean all exhaust connection points using a wire brush to remove carbon buildup, corrosion, and old gasket material. Inspect flanges for warping or damage—replace if not flat. Check rubber hangers for tears, excessive wear, or hardening; replace if degraded. Inspect clamps for thread damage or deformation; replace if questionable.
8. 8

   Position new resonator assembly
   Apply a thin coat of anti-seize compound to clamp bolt threads (if reusing clamps) and flange stud threads. Place the new resonator assembly on the support jack and raise into approximate position. Align the inlet and outlet pipes with their mating connections but do not fully seat yet.
9. 9

   Install exhaust hangers
   Guide rubber exhaust hangers onto their mounting studs. Use the exhaust hanger tool or lubricate hangers with soapy water to ease installation. Ensure hangers are fully seated on studs and resonator section is hanging at correct height with minimal tension. Adjust support jack as needed to align connections properly.
10. 10

    Connect forward exhaust joint
    Align the resonator inlet with the forward exhaust section outlet. Install new gaskets if flange-type connection is used. Install clamp around the joint or thread flange nuts onto studs. Hand-tighten fasteners only at this stage to allow for final alignment adjustment.
11. 11

    Connect rear exhaust joint
    Align the resonator outlet with the rear exhaust section inlet. Install new gaskets if applicable. Install clamp or thread flange nuts onto studs. Hand-tighten fasteners. Check overall alignment of the entire exhaust section—pipes should hang evenly with adequate clearance from chassis, driveshaft, and rear suspension components. Adjust as necessary before final torquing.
12. 12

    Torque exhaust connections
    Once alignment is verified, torque exhaust clamp bolts and flange nuts to the OEM-specified value (verify in factory service data — typical exhaust flange/clamp hardware for M8 fasteners is approximately 23 Nm / 17 lb-ft, but confirm against Aston Martin factory data) in a cross-pattern if multiple bolts per clamp. Do not exceed OEM torque. Torque exhaust hanger mounting bolts (if hanger brackets were removed) to the OEM-specified value (verify in factory service data). Remove support jack from under exhaust system. Note: Torque exhaust hanger mounting bolts (if hanger brackets were removed) to the OEM-specified value — verify against factory documentation. Note: Once alignment is verified, torque all exhaust clamp bolts to the OEM-specified value (commonly 20-35 Nm / 15-26 lb-ft for M8-M10 exhaust fasteners) in a cross-pattern if multiple bolts per clamp. Torque flange nuts to the OEM specification — verify against factory documentation before final tightening.
    Torque spec

    Exhaust Clamps55 Nm (41 lb-ft)

    Hanger Bolts27 Nm (20 lb-ft)
13. 13

    Reinstall oxygen sensors
    If oxygen sensors were removed, apply anti-seize compound to sensor threads (avoid getting compound on sensor tip). If oxygen sensors were removed, thread sensors into bungs by hand, then torque to the OEM-specified value (verify in factory service data — commonly around 40-45 Nm / 30-33 lb-ft) using an oxygen sensor socket. Reconnect electrical connectors—ensure they click fully into place and are routed away from heat sources. Note: Thread sensors into bungs by hand, then torque to the OEM-specified value (commonly ~40-45 Nm / 30-33 lb-ft, reduced if anti-seize is used) using an oxygen sensor socket.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)

Reassembly

1. Reassembly is integrated into the procedure steps above.
2. Ensure all exhaust connections are tight and properly torqued before lowering vehicle.
3. Verify exhaust hangers are properly seated and system has adequate clearance throughout its length.

Verification

• Lower vehicle and start engine. Listen for exhaust leaks at all connection points—a hissing or ticking sound indicates a leak requiring re-torquing or gasket replacement.
• Allow engine to reach operating temperature and verify no unusual exhaust odors enter the cabin.
• Perform a test drive and listen for rattles, vibrations, or exhaust contact with chassis components. Re-check all fastener torque if any issues are detected.
• After 50-100 miles of driving, re-inspect exhaust clamp and flange torque as thermal cycling may cause initial settling.

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