This procedure covers the removal and installation of the front exhaust pipe (downpipe) on the 3.5L EcoBoost engine, connecting the turbocharger outlets to the catalytic converters.

Warnings

Tools required

Parts

• Front exhaust pipe/downpipe assembly × 1 — Use OEM specification
• Turbocharger-to-front pipe gaskets × 2 — Use OEM specification
• Front pipe-to-catalytic converter gaskets × 1 — Use OEM specification
• Exhaust flange nuts and bolts kit × 1 — Use OEM specification

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 at manufacturer-specified lift points
5. Spray all exhaust fasteners with penetrating oil and allow to soak for at least 15 minutes
6. Verify adequate working clearance underneath the vehicle

Procedure

1. 1

   Disconnect oxygen sensors
   Locate the two upstream oxygen sensors on the front pipe assembly. Disconnect the electrical connectors by pressing the release tabs and pulling apart. Using a 22mm oxygen sensor socket, carefully remove both oxygen sensors from the front pipe. If sensors are being reused, inspect threads and apply anti-seize to threads only (not the sensor tip) before setting aside.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
2. 2

   Remove heat shield fasteners
   Remove the heat shield bolts securing the exhaust heat shields around the front pipe area. There are typically multiple shields that may need to be removed or loosened for clearance. Set shields and hardware aside for reinstallation.
   Torque spec

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

   Support the front pipe
   Position a floor jack with a block of wood under the front pipe assembly to support its weight during removal. Raise the jack just enough to take the load off the hangers and flanges, but do not apply upward pressure.
4. 4

   Disconnect exhaust hangers
   Locate the rubber exhaust hangers supporting the front pipe. Remove the hanger bolts or carefully pry the hangers off their mounting studs using a pry bar. The front pipe has multiple hanger points that must be disconnected.
   Torque spec

   Hanger Bolts23 Nm (17 lb-ft)
5. 5

   Remove turbocharger flange connection
   Locate the flange connection where the front pipe connects to both turbocharger outlets. Remove the exhaust flange bolts (typically 4 bolts per turbo, 8 total) connecting the front pipe to the twin turbocharger downpipe outlets. Note the condition of the gaskets for replacement.
   ⚠These bolts are highly susceptible to corrosion. If bolts break, the studs may need to be extracted from the turbocharger housing, which requires additional labor.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
6. 6

   Remove catalytic converter flange connection
   At the rear of the front pipe, remove the flange bolts connecting the front pipe to the catalytic converter assembly. This is typically a 4-bolt connection. Support the weight of the front pipe with the jack as you remove the final fasteners.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
7. 7

   Remove front pipe assembly
   Carefully lower the jack while guiding the front pipe assembly down and away from the vehicle. The pipe may need to be maneuvered at an angle to clear the transmission crossmember and other components. Once free, remove the old gaskets from all flange surfaces and inspect for damage.
   ⚠The front pipe assembly weighs approximately 25-30 lbs and has sharp edges. Use caution when maneuvering it out of the vehicle.
8. 8

   Clean mating surfaces
   Using a wire brush and gasket scraper, thoroughly clean all flange mating surfaces on the turbocharger outlets and catalytic converter inlet. Remove all old gasket material, carbon buildup, and corrosion. Wipe surfaces clean with parts cleaner. Inspect flanges for cracks, warping, or damage.
9. 9

   Prepare new front pipe
   If installing a new front pipe, transfer any reusable brackets or components from the old pipe. Install new gaskets on the turbocharger flange connections and catalytic converter flange connection. Apply a thin coat of anti-seize to all exhaust flange bolt threads.
10. 10

    Install front pipe assembly
    Position the new front pipe on the jack and carefully raise it into place. Align the rear flange with the catalytic converter first, then maneuver the front flanges to align with both turbocharger outlets. This may require multiple adjustments. Install flange bolts hand-tight at all three connection points before torquing.
    ℹ️Do not fully tighten any connection until all flanges are aligned and bolts are started. This allows for adjustment during final positioning.
11. 11

    Torque flange connections
    Starting with the turbocharger flange connections, torque the exhaust flange bolts in a criss-cross pattern to specification. Then torque the catalytic converter flange bolts in a criss-cross pattern. Verify all connections are secure and flanges are seated properly.
    Torque spec

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

    Reconnect exhaust hangers
    Reinstall all exhaust hanger connections, ensuring rubber isolators are properly seated. Torque hanger bolts to specification. Verify the front pipe is properly supported and has adequate clearance from surrounding components, frame rails, and the driveshaft.
    Torque spec

    Hanger Bolts23 Nm (17 lb-ft)
13. 13

    Install oxygen sensors
    Install both upstream oxygen sensors into the front pipe. Apply anti-seize compound to the threads only, keeping compound away from the sensor tip. Thread sensors in by hand first, then torque to specification using the oxygen sensor socket. Reconnect both electrical connectors until they click into place.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
14. 14

    Reinstall heat shields
    Reinstall all heat shields that were removed or loosened during the procedure. Ensure shields are properly positioned and do not contact the exhaust pipe directly. Torque heat shield bolts to specification.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Remove jack stands and carefully lower the vehicle to the ground
2. Double-check that all exhaust connections are secure and properly torqued
3. Verify oxygen sensor electrical connectors are fully engaged
4. Ensure no tools or parts were left in the engine compartment or under the vehicle

Verification

• Start the engine and listen for exhaust leaks at all flange connections. A hissing sound indicates a leak that must be addressed
• Perform a visual inspection of all connections while the engine is running to check for exhaust gas escaping
• Allow engine to reach operating temperature and verify no exhaust leaks develop under heat expansion
• Check for Check Engine Light illumination. If present, scan for codes related to oxygen sensors or exhaust system
• Verify the front pipe has adequate clearance from all surrounding components and does not contact the frame, driveshaft, or transmission
• After a short test drive, re-inspect all connections and verify no rattles or abnormal noises are present

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