This procedure covers removal and replacement of the intermediate exhaust pipe on a 2011-2014 Ford F-150 with 3.5L EcoBoost engine, including flange disconnection, hanger removal, and oxygen sensor handling.

Warnings

Tools required

Parts

• Intermediate exhaust pipe assembly × 1 — Use OEM specification
• Exhaust flange gaskets × 2 — Use OEM specification
• Exhaust flange bolts (if corroded) × 4 — M10 x 1.5 flange bolts

Preparation

1. Park vehicle on level surface and apply parking brake
2. Place wheel chocks behind rear wheels
3. Allow exhaust system to cool completely (minimum 1 hour after engine operation)
4. Raise front of vehicle and support securely on jack stands at frame rails, maintaining clearance for exhaust work
5. Spray all exhaust flange bolts and hanger bolts with penetrating oil and allow to soak
6. Locate and identify oxygen sensor connectors on intermediate pipe section

Procedure

1. 1

   Disconnect oxygen sensors
   Locate the oxygen sensor electrical connectors on the intermediate pipe. Press the release tab and carefully disconnect each connector. If sensors are being reused with new pipe, use oxygen sensor socket to remove sensors from old pipe. Inspect sensor threads and apply anti-seize to threads only, avoiding sensor tip.
2. 2

   Remove heat shields (if equipped)
   Remove any heat shields covering the intermediate pipe connections using appropriate socket. Some models have shields over flanges or near transmission crossmember. Set shields aside with hardware for reinstallation.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
3. 3

   Disconnect front flange from turbocharger outlet
   Locate the front flange connection where intermediate pipe connects to turbocharger downpipe or catalytic converter outlet. Remove the flange bolts using deep socket and extension. Support the intermediate pipe weight to prevent binding. Separate the flange and remove old gasket.
   ⚠Flange bolts may be severely corroded. If bolt breaks, you may need to drill out and re-tap the flange or replace the upstream component.
   Torque spec

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

   Disconnect rear flange connection
   Move to rear flange where intermediate pipe connects to rear exhaust section (muffler assembly). Remove exhaust flange bolts using socket and extension. Support rear exhaust section to prevent it from dropping. Separate the connection and remove old gasket.
   ℹ️On some models, this connection may be a slip-fit clamp instead of bolted flange. Loosen clamp bolts if applicable.
   Torque spec

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

   Remove exhaust hanger supports
   Locate rubber exhaust hangers supporting the intermediate pipe. There are typically 1-2 hangers on this section. Use pry bar to carefully work hanger studs out of rubber isolators. If hangers are seized, apply penetrating oil and twist pipe while prying.
   Torque spec

   Hanger Bolts23 Nm (17 lb-ft)
6. 6

   Remove intermediate pipe
   With all connections and hangers disconnected, maneuver intermediate pipe down and out from under vehicle. May need to rotate or angle pipe to clear frame rails, cross members, and front differential. Inspect old pipe for damage or excessive corrosion to confirm replacement necessity.
7. 7

   Clean flange surfaces and inspect
   Use wire brush to thoroughly clean both flange mating surfaces on turbocharger outlet pipe and rear exhaust section. Remove all old gasket material, rust, and carbon deposits. Inspect flanges for cracks, warping, or damage. Check that flange bolt holes are not wallowed out or stripped.
8. 8

   Install oxygen sensors in new pipe (if applicable)
   If reusing oxygen sensors or installing new sensors, apply anti-seize compound to sensor threads only. Do not get anti-seize on sensor tip as this will damage the sensor. Thread sensors into new intermediate pipe by hand first, then tighten to specification using oxygen sensor socket.
   ⚠Never apply anti-seize to oxygen sensor tip. Only apply to threads. Contamination of sensor element will cause malfunction and check engine light.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
9. 9

   Position new intermediate pipe
   Maneuver new intermediate pipe into position under vehicle, routing through frame rails and around front differential. Align pipe so that both front and rear flanges are close to their mating surfaces and hanger studs align with rubber isolators. Do not fully connect anything yet.
10. 10

    Install exhaust hangers
    Insert hanger studs into rubber isolator mounts. Use pry bar if needed to stretch isolators over studs. Ensure hangers are fully seated and pipe is supported in proper position. This will help align flanges for connection.
11. 11

    Connect rear flange to exhaust system
    Position new flange gasket at rear connection between intermediate pipe and rear exhaust section. Align flanges and install exhaust flange bolts with anti-seize compound applied to threads. Start all bolts by hand first. Tighten bolts in cross pattern to specification using torque wrench.
    ℹ️Anti-seize is critical on exhaust fasteners to allow future removal. Apply to bolt threads before installation.
    Torque spec

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

    Connect front flange to turbocharger outlet
    Position new flange gasket at front connection between intermediate pipe and turbocharger downpipe or catalytic converter. Align flanges carefully ensuring gasket stays centered. Install flange bolts and start all by hand. Tighten bolts in cross pattern to specification using torque wrench.
    Torque spec

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

    Reinstall heat shields
    If heat shields were removed, position them back in place over flange connections and around pipe as originally installed. Install shield mounting bolts and tighten to specification.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
14. 14

    Connect oxygen sensor electrical connectors
    Route oxygen sensor wiring to original connectors. Connect each sensor harness ensuring connection clicks into place securely. Verify wiring is not touching hot exhaust components and is properly secured with any factory clips or routing guides.

Reassembly

1. Verify all exhaust connections are tight and torqued to specification
2. Confirm oxygen sensor wiring is connected and properly routed away from heat sources
3. Check that all exhaust hangers are fully seated in rubber isolators
4. Ensure no tools or parts have been left under vehicle
5. Lower vehicle from jack stands carefully

Verification

• Start engine and allow to idle. Listen for exhaust leaks at both flange connections - a ticking or hissing sound indicates leak requiring retightening or gasket replacement
• Visually inspect all connections while engine is running for any signs of exhaust escaping
• Rev engine to 2000-2500 RPM and verify no exhaust leaks develop under increased pressure
• Check that no check engine light or oxygen sensor codes appear after test drive
• Test drive vehicle for 10-15 minutes, then re-inspect all connections for leaks or loosening
• Verify exhaust system does not contact frame, driveshaft, or suspension components during full suspension travel

More procedures for this vehicle