This procedure covers removal and replacement of the front exhaust pipe (downpipe) on the 3.5L EcoBoost V6 engine, connecting the turbocharger outlets to the catalytic converters.

Warnings

Tools required

Parts

• Front exhaust pipe assembly × 1 — Use OEM Ford part or quality aftermarket equivalent
• Exhaust flange gaskets (turbo to pipe) × 2 — Ford OEM turbo flange gasket set
• Catalytic converter flange gaskets × 1 — Ford OEM or equivalent donut gasket
• Exhaust hanger isolators (if deteriorated) — Replace as needed

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow exhaust system to cool completely (minimum 2 hours after engine shutdown)
3. Raise vehicle and support securely on jack stands at frame rails - minimum 18 inches of ground clearance recommended
4. Apply penetrating oil to all exhaust flange bolts, oxygen sensor threads, and hanger bolts if not already done 24 hours prior
5. Disconnect negative battery terminal to prevent O2 sensor fault codes during service
6. Remove factory skid plate if equipped (8 mounting bolts)
7. Inspect exhaust system for any aftermarket modifications that may alter procedure

Procedure

1. 1

   Remove heat shields
   Remove the turbocharger heat shields by removing the heat shield bolts. There are multiple shields covering the turbo housings and front pipe area. Tag shield locations for proper reinstallation. Note that some shields may be shared with other components.
   Torque spec

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

   Disconnect oxygen sensors
   Locate the upstream oxygen sensors on each turbocharger outlet (2 sensors total). Disconnect the electrical connectors by pressing the release tabs. Using the oxygen sensor socket, carefully remove both O2 sensors from the front pipe. Turn counterclockwise and be prepared for seized sensors - apply heat if necessary but avoid torch contact with wiring. If sensors are being reused, inspect threads and replace if damaged.
   ⚠Never apply anti-seize to oxygen sensor shells or bodies, only to threads. Contamination will cause sensor failure.
   Torque spec

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

   Support front pipe assembly
   The front pipe is heavy and awkward. Position a floor jack or transmission jack under the center of the front pipe assembly to support its weight during removal. Use a block of wood on the jack pad to protect the pipe and provide stable contact.
   ⚠Front pipe assembly weighs approximately 25-35 lbs and will drop when fasteners are removed. Ensure adequate support.
4. 4

   Disconnect exhaust hangers
   Locate the rubber exhaust hangers supporting the front pipe (typically 2 hangers). Remove the hanger bolts or pry the hanger loops off the mounting studs using a pry bar. Inspect rubber isolators for cracks or deterioration and replace if worn. Mark hanger positions if asymmetrical.
   Torque spec

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

   Remove turbo-to-front pipe flange bolts
   Remove the exhaust flange bolts connecting both turbocharger outlets to the front pipe. There are 3 bolts per turbo flange (6 bolts total). Access is tight - use a combination of extensions and universal joint adapters. Work bolts evenly to avoid binding. If bolts break, drill out and re-tap threads or use helicoil insert.
   ⚠These bolts frequently seize and break. If bolts break flush, drilling and extraction will add significant time. Consider heating fasteners with torch if penetrating oil fails.
   Torque spec

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

   Remove front pipe to catalytic converter connection
   At the rear of the front pipe assembly, remove the flange bolts connecting to the catalytic converter or mid-pipe section. This connection uses either a 3-bolt flange or band clamp depending on exact configuration. Remove all fasteners and separate the connection. Note any spring-loaded joints that may require compression during reassembly.
   ℹ️Some configurations use a spring-loaded ball joint connection. Mark alignment before separation.
   Torque spec

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

   Remove front pipe assembly
   With all fasteners removed and assembly supported by jack, carefully lower and maneuver the front pipe assembly out from under the vehicle. The dual-pipe design requires specific angle manipulation - typically rotate assembly and remove driver side first, then passenger side. Work slowly to avoid damaging oxygen sensor bungs or surrounding components.
   ⚠Assembly must navigate around steering linkage, driveshaft, and crossmember. Do not force - reposition jack and try different angles.
8. 8

   Clean mating surfaces
   With front pipe removed, thoroughly clean all exhaust flange mating surfaces on both turbocharger outlets and the catalytic converter inlet. Use a wire brush and scraper to remove all old gasket material, carbon buildup, and corrosion. Inspect flange faces for warping or damage. Check turbo outlet flanges for cracks which would indicate turbo failure.
   ℹ️This is critical for preventing exhaust leaks. Uneven surfaces will leak regardless of new gaskets.
9. 9

   Install new oxygen sensors
   Apply a thin coating of anti-seize compound to the threads only of the oxygen sensors (new or reused). Thread sensors by hand into the new front pipe assembly until fully seated. Tighten to specification using the oxygen sensor socket. Ensure connectors are positioned for easy reconnection and wiring routes do not contact hot exhaust surfaces.
   ⚠Apply anti-seize to threads only. Keep anti-seize away from sensor tip and perforated shell. Contamination causes permanent sensor damage.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
10. 10

    Install new front pipe assembly
    Position the new front pipe assembly on the jack and raise into approximate position. Install new flange gaskets at all connection points - do not reuse old gaskets. Align the rear connection to the catalytic converter first and start fasteners hand-tight. Then align both turbo outlet connections and start those fasteners hand-tight. Work all connections to ensure proper alignment before final torquing.
    ℹ️Do not fully tighten any connection until all fasteners are started. This allows alignment adjustment.
11. 11

    Torque turbo flange connections
    Apply a thin coating of anti-seize to the threads of the new exhaust flange bolts for the turbocharger connections. Install and tighten bolts in a star pattern to specification. Work each flange evenly, alternating between bolts to ensure even gasket compression and proper sealing.
    ℹ️Anti-seize on these bolts is critical for future service and is specified by Ford for this application.
    Torque spec

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

    Torque catalytic converter connection
    Tighten the rear flange bolts connecting the front pipe to the catalytic converter to specification. Use a star pattern for even gasket compression. If connection uses a spring-loaded ball joint, ensure alignment marks match and joint moves freely before final torque.
    Torque spec

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

    Reinstall exhaust hangers
    Reinstall the exhaust hanger isolators to their mounting points. Install and torque hanger bolts to specification. Ensure pipe is properly supported and aligned - there should be no strain on any flange connection. Check clearance to all surrounding components including driveshaft, crossmember, and frame rails.
    Torque spec

    Hanger Bolts23 Nm (17 lb-ft)
14. 14

    Reinstall heat shields and connect sensors
    Reinstall all turbocharger and exhaust heat shields in their original positions. Torque heat shield bolts to specification. Reconnect both oxygen sensor electrical connectors and verify secure latch engagement. Route wiring away from hot exhaust components and ensure no contact points.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
15. 15

    Final inspection and reinstallation
    Reinstall factory skid plate if equipped. Verify all fasteners are torqued, all electrical connectors are engaged, and exhaust system has proper clearance throughout. Reconnect negative battery terminal. Lower vehicle from jack stands.
    ℹ️Do not start engine until final verification is complete.

Reassembly

1. Verify all exhaust connections are properly torqued using star pattern technique
2. Ensure minimum 1/2 inch clearance between exhaust system and all surrounding components
3. Confirm oxygen sensor wiring has no contact points with exhaust or moving components
4. Check that all heat shields are properly secured and positioned
5. Verify exhaust hangers are properly supporting system with no strain on flanges

Verification

• Start engine and allow to idle. Listen for any exhaust leaks at flange connections - ticking or hissing indicates leak
• With engine at idle, inspect all connections for visible exhaust gas escaping. Use soap water solution if leak suspected but not visible
• Rev engine to 2500 RPM briefly and recheck all connections under increased exhaust pressure
• Verify no check engine light illumination and scan for oxygen sensor fault codes
• After engine reaches operating temperature, re-inspect all connections for leaks as gaskets fully seat
• Test drive vehicle and verify normal operation, no unusual noises, and proper turbo boost response
• After 50-100 miles, re-check all flange bolt torque values as exhaust gaskets may settle slightly

More procedures for this vehicle