Remove and replace the front exhaust pipe (Y-pipe) assembly connecting the exhaust manifolds to the catalytic converters on the 5.0L Coyote V8 engine.

Warnings

Tools required

Parts

• Front pipe/Y-pipe assembly × 1 — Use OEM specification
• Exhaust flange gaskets (manifold-to-front pipe) × 2 — Use OEM specification
• Exhaust flange gaskets (front pipe-to-catalytic converter) × 2 — Use OEM specification
• Oxygen sensor (if damaged during removal) × 2 — Use OEM specification

Preparation

1. Park vehicle on level surface and apply parking brake
2. Place wheel chocks behind rear wheels
3. Ensure engine and exhaust system are completely cool to the touch
4. Spray all exhaust flange bolts, oxygen sensor threads, and hanger bolts with penetrating oil
5. Raise front of vehicle and secure on jack stands at frame rails behind front wheels
6. Verify vehicle is stable before working underneath
7. Remove plastic undertray panels if equipped to access exhaust components

Procedure

1. 1

   Disconnect oxygen sensors
   Locate both upstream oxygen sensors in the front pipe assembly. Disconnect electrical connectors by pressing release tabs and pulling away from sensors. Using a 22mm oxygen sensor socket, carefully remove both oxygen sensors from the front pipe. If sensors are seized, apply heat with a heat gun (not torch) and additional penetrating oil. Set sensors aside if reusing.
2. 2

   Remove heat shields
   Remove any heat shields covering the front pipe assembly using a 13mm socket. Heat shields are typically secured with sheet metal bolts. Set shields and hardware aside for reinstallation.
   Torque spec

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

   Support front pipe assembly
   Position a transmission jack or sturdy support under the center of the front pipe assembly. Raise jack until it just contacts the pipe to support weight during removal. Alternatively, have an assistant ready to support the assembly.
4. 4

   Disconnect front pipe from catalytic converters
   Locate the flange connection where the front pipe meets the catalytic converters (approximately mid-vehicle). Remove the flange bolts using a 15mm socket. There are typically 4 bolts per side (8 total). Use a universal joint and extension for better access. Keep bolts organized for reinstallation.
   ⚠Bolts may be extremely corroded. Apply additional penetrating oil and allow to soak if resistance is encountered.
   Torque spec

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

   Remove exhaust hanger supports
   Locate rubber exhaust hangers supporting the front pipe assembly. Use a pry bar or screwdriver to carefully work the exhaust hangers off their mounting points. Note the position of each hanger for reassembly. If hangers are deteriorated, mark for replacement.
   Torque spec

   Hanger Bolts26 Nm (19 lb-ft)
6. 6

   Disconnect front pipe from exhaust manifolds
   Working from above or below as needed, locate the flange connections at both exhaust manifolds. Remove the exhaust flange bolts connecting the front pipe to each manifold using a 15mm socket with universal joint and extensions. There are typically 3 bolts per side. Work carefully in the tight engine bay space.
   ⚠Access to passenger side bolts is limited. A flexible universal joint is essential for proper access.
   Torque spec

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

   Remove front pipe assembly
   With all connections disconnected, carefully lower and maneuver the front pipe assembly down and out from under the vehicle. The assembly is heavy and may require rotating and angling to clear frame rails, crossmembers, and steering components. Work slowly to avoid damaging brake lines or other components.
8. 8

   Clean mounting surfaces
   Using a wire brush and gasket scraper, thoroughly clean all exhaust flange surfaces at the manifolds and catalytic converter connections. Remove all old gasket material, carbon buildup, and corrosion. Clean surfaces ensure proper sealing and prevent exhaust leaks.
9. 9

   Install new front pipe assembly
   Position new flange gaskets at the exhaust manifold connections. Maneuver the new front pipe assembly into position, aligning it first with the manifold flanges. Install flange bolts finger-tight at the manifolds. Then align the rear flanges with the catalytic converters and install those bolts finger-tight. Do not fully tighten any bolts yet.
10. 10

    Reconnect exhaust hangers
    Reattach rubber exhaust hangers to their mounting points, ensuring the front pipe assembly is properly supported and aligned. Use a lubricant like soapy water on hangers to ease installation if needed.
11. 11

    Torque manifold flange bolts
    Apply anti-seize compound to the threads of the exhaust flange bolts at the manifold connections. Starting from the center bolt and working outward, torque the bolts to specification using a torque wrench. Torque in a cross pattern to ensure even clamping pressure.
    Torque spec

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

    Torque catalytic converter flange bolts
    Apply anti-seize compound to the threads of the flange bolts at the catalytic converter connections. Torque these bolts to specification using a cross pattern, starting from the center and working outward on each flange.
    Torque spec

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

    Install oxygen sensors
    Apply a thin coat of anti-seize compound to the threads of both oxygen sensors (avoid getting anti-seize on the sensor tip). Thread sensors into the front pipe by hand to avoid cross-threading. Once hand-tight, torque oxygen sensors to specification using the 22mm oxygen sensor socket and torque wrench. Reconnect electrical connectors to both sensors, ensuring they click securely into place.
    Torque spec

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

    Reinstall heat shields
    Reinstall heat shields over the front pipe assembly and secure with bolts. Torque heat shield bolts to specification. Ensure heat shields are properly positioned and not contacting other components.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Reinstall any undertray panels or splash shields removed during preparation
2. Lower vehicle from jack stands
3. Remove wheel chocks

Verification

• Start engine and allow to reach operating temperature while monitoring for exhaust leaks at all flange connections
• Listen for any unusual exhaust sounds or hissing that would indicate a leak
• Verify oxygen sensor operation by checking for diagnostic trouble codes with a scan tool
• After initial warm-up cycle, re-inspect all flange connections for any signs of leakage
• Perform a test drive and verify normal exhaust sound and engine performance
• After 50-100 miles of driving, re-check all exhaust flange bolt torque and retighten if necessary

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