This procedure covers the removal and replacement of the downpipe on a 2014 Ram 2500 with 6.7L Cummins diesel engine, including disconnection of oxygen sensors and exhaust components.

Warnings

Tools required

Parts

• Downpipe assembly × 1 — Use OEM specification or aftermarket equivalent
• Exhaust flange gasket × 1 — Turbo to downpipe gasket
• Exhaust flange bolts × 3 — M10 exhaust flange bolts
• Oxygen sensor (if damaged) × 1 — Downstream O2 sensor

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 2 hours after engine operation)
4. Disconnect negative battery cable to prevent O2 sensor codes during removal
5. Raise front of vehicle and support securely on jack stands at frame rails
6. Spray all exhaust fasteners with penetrating oil and allow to soak for 15-30 minutes

Procedure

1. 1

   Remove heat shields
   Locate and remove the heat shields covering the downpipe. Remove bolts securing the heat shields to the chassis and downpipe. Set shields and hardware aside for reinstallation.
   Torque spec

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

   Disconnect oxygen sensor
   Locate the downstream oxygen sensor on the downpipe. Disconnect the electrical connector by pressing the release tab. Using an O2 sensor socket or 22mm wrench, carefully unthread the sensor from the downpipe. Rotate counterclockwise with steady pressure to avoid breaking the sensor.
   ⚠Do not allow contaminants to enter the sensor threads or tip. Keep sensor protected if reusing.
   Torque spec

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

   Remove hanger support bolts
   Locate the exhaust hanger brackets supporting the downpipe. Remove the bolts securing the hangers to the chassis crossmember. Support the downpipe with one hand while removing the final hanger to prevent sudden movement.
   Torque spec

   Hanger Bolts27 Nm (20 lb-ft)
4. 4

   Disconnect downpipe from turbo outlet
   Locate the V-band clamp or flange connection at the turbocharger outlet. Remove the exhaust flange bolts connecting the downpipe to the turbo. There are typically 3 bolts in a triangular pattern. Apply additional penetrating oil if bolts resist removal. Once bolts are removed, support the downpipe to prevent it from falling.
   ⚠Bolts may be seized from heat and corrosion. Use proper size socket to avoid rounding bolt heads.
   Torque spec

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

   Disconnect downpipe from mid-pipe
   Move to the rear connection where the downpipe meets the mid-pipe section. Remove the flange bolts securing this connection. There are typically 2-4 bolts at this junction. Support both pipe sections to prevent stress on remaining exhaust components.
   Torque spec

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

   Remove downpipe assembly
   With all connections and hangers disconnected, carefully lower and maneuver the downpipe out from under the vehicle. It may be necessary to rotate or angle the pipe to clear the crossmember and other chassis components. Inspect the removed downpipe for damage or excessive wear.
   ⚠Downpipe is heavy and awkward. Use proper lifting technique or have an assistant help support the component.
7. 7

   Clean mounting surfaces
   Use a wire brush to thoroughly clean all flange mating surfaces at the turbo outlet and mid-pipe connection. Remove all old gasket material, carbon deposits, and corrosion. Wipe surfaces clean with a rag. Inspect flange faces for warping or damage.
   ℹ️Clean mounting surfaces ensure proper seal and prevent exhaust leaks.
8. 8

   Install new turbo flange gasket
   Position the new exhaust flange gasket onto the turbocharger outlet flange. Ensure the gasket is properly aligned with all bolt holes. Apply a thin coat of anti-seize to the threads of the new or cleaned exhaust flange bolts.
9. 9

   Install new downpipe
   Maneuver the new downpipe into position, aligning it with the turbo outlet first. Start all three exhaust flange bolts by hand at the turbo connection but do not tighten. Align the rear flange with the mid-pipe and start those flange bolts by hand. Ensure all hangers align with their mounting points.
   ℹ️Leave all connections loose until all bolts are started to allow for proper alignment.
10. 10

    Torque turbo connection
    Using a torque wrench, tighten the exhaust flange bolts at the turbo outlet in a cross pattern to ensure even gasket compression. Torque to specification.
    Torque spec

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

    Torque mid-pipe connection
    Torque the flange bolts at the downpipe-to-mid-pipe connection in a cross pattern to specification. Verify that the pipe alignment is correct and no stress is placed on the connections.
    Torque spec

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

    Install hanger supports
    Align the exhaust hangers with their mounting points on the chassis. Install and torque the hanger bolts to specification. Verify the downpipe has adequate clearance from the driveshaft, chassis, and other components.
    Torque spec

    Hanger Bolts27 Nm (20 lb-ft)
13. 13

    Install oxygen sensor
    Apply a small amount of anti-seize compound to the threads only of the oxygen sensor (avoid getting anti-seize on the sensor tip). Thread the sensor into the downpipe by hand, then torque to specification using an O2 sensor socket. Reconnect the electrical connector until it clicks into place.
    ⚠Do not over-torque oxygen sensor as this can damage the threads or sensor body.
    Torque spec

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

    Reinstall heat shields
    Position the heat shields over the downpipe and align with mounting holes. Install and torque heat shield bolts to specification. Ensure shields do not contact moving components or create rattles.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Reconnect negative battery cable
2. Lower vehicle from jack stands
3. Perform visual inspection of all connections to verify proper installation and clearance

Verification

• Start engine and allow to idle. Listen for exhaust leaks at all connection points
• Check for unusual vibrations or rattles from exhaust system
• Verify O2 sensor connector is secure and check engine light is not illuminated for O2 sensor codes
• Perform a test drive and monitor for exhaust leaks under load
• Recheck all torque specifications after first 50-100 miles of operation
• Inspect for exhaust soot or discoloration around flanges indicating potential leaks

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