This procedure covers the removal and replacement of the intermediate pipe (mid-pipe) between the catalytic converters and the muffler on the 2015-2020 Ford F-150 with the 3.5L EcoBoost V6 engine.

Warnings

Tools required

Parts

• Intermediate pipe assembly × 1 — Use OEM specification or aftermarket equivalent
• Exhaust flange gaskets × 2 — Use OEM specification
• Exhaust flange bolts and nuts × 1 — Replace if corroded
• Rubber exhaust hangers × 1 — Replace if damaged or deteriorated

Preparation

1. Park vehicle on level ground and apply parking brake
2. Place wheel chocks behind rear wheels
3. Allow exhaust system to cool completely (minimum 2 hours after last operation)
4. Raise front of vehicle and support securely on jack stands
5. Spray all exhaust fasteners with penetrating oil and allow to soak for 15-30 minutes

Procedure

1. 1

   Remove heat shield fasteners
   If equipped with heat shields covering the intermediate pipe, remove the heat shield mounting bolts using a 10mm socket. There are typically 2-4 bolts securing each heat shield section. Set heat shields aside.
   Torque spec

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

   Disconnect front exhaust flange
   Locate the front flange connection where the intermediate pipe connects to the catalytic converter outlets. Using a 15mm socket, remove the two flange bolts and nuts. Support the intermediate pipe weight as you remove the last fastener. Separate the flange connection and remove the old gasket.
   ⚠Bolts may be severely corroded. Apply heat if necessary, but be aware of nearby components and fuel lines.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
3. 3

   Disconnect rear exhaust flange
   Move to the rear flange connection where the intermediate pipe connects to the muffler assembly. Using a 15mm socket, remove the two flange bolts and nuts at this connection. Keep the intermediate pipe supported to prevent it from falling.
   Torque spec

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

   Remove exhaust hanger connections
   Locate the rubber exhaust hangers supporting the intermediate pipe (typically 2 hangers). Using a pry bar or exhaust hanger tool, carefully pry the hanger loops off the rubber isolators. Work carefully to avoid tearing the rubber hangers if they will be reused.
   ℹ️Spray soapy water on rubber hangers to ease removal and installation.
5. 5

   Remove intermediate pipe
   With all fasteners and hangers disconnected, carefully lower and remove the intermediate pipe from the vehicle. Maneuver it past the frame rails, driveshaft, and crossmembers. Inspect the removal path to avoid damaging brake lines or wiring.
6. 6

   Clean flange surfaces
   Using a wire brush and scraper, thoroughly clean both the front and rear exhaust flange mating surfaces on the catalytic converter outlet and muffler inlet. Remove all old gasket material, rust, and carbon deposits to ensure proper sealing of new gaskets.
7. 7

   Inspect and prepare new intermediate pipe
   Inspect the new intermediate pipe for any shipping damage. Verify flange bolt holes align properly. If reusing exhaust hangers, inspect them for cracks or deterioration and replace if necessary. Position new exhaust flange gaskets on the flanges.
8. 8

   Position new intermediate pipe
   Carefully maneuver the new intermediate pipe into position under the vehicle. Align the front flange with the catalytic converter outlet and the rear flange with the muffler inlet. Install the pipe onto the rubber exhaust hangers, ensuring proper alignment before fastening flanges.
9. 9

   Install front flange connection
   Position the new gasket between the front flange surfaces. Apply anti-seize compound to the flange bolt threads. Install both flange bolts and nuts finger-tight. Do not fully tighten yet to allow for alignment adjustment.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
10. 10

    Install rear flange connection
    Position the new gasket between the rear flange surfaces. Apply anti-seize compound to the flange bolt threads. Install both flange bolts and nuts finger-tight. Verify the intermediate pipe is properly seated on all exhaust hangers and has adequate clearance from frame, driveshaft, and fuel lines.
    Torque spec

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

    Torque flange fasteners
    Using a torque wrench, tighten the front flange bolts to specification in a cross pattern. Then torque the rear flange bolts to specification in a cross pattern. Double-check that the pipe maintains proper clearance from all surrounding components after tightening.
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)
12. 12

    Reinstall heat shields
    If heat shields were removed, position them back over the intermediate pipe. Install and torque the heat shield mounting bolts to specification. Ensure heat shields do not contact the pipe directly and have proper clearance.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Verify all exhaust hangers are properly seated and supporting the pipe
2. Confirm minimum 1 inch clearance between exhaust pipe and all fuel lines, brake lines, wiring, and driveshaft
3. Ensure heat shields are secure and properly positioned
4. Lower vehicle from jack stands

Verification

• Start engine and allow to idle, listening for exhaust leaks at both flange connections
• Check for any unusual vibrations or rattling from the exhaust system
• Visually inspect all connections for signs of exhaust gas leakage (soot or discoloration)
• Take vehicle for short test drive and re-verify no exhaust leaks or contact points when system is hot
• After test drive, re-check all flange bolts to ensure they remain properly torqued

More procedures for this vehicle