DPF Delete Pipe

This procedure removes the diesel particulate filter (DPF) and replaces it with a delete pipe on 1994-2007 Dodge Ram 2500 equipped with 5.9L Cummins diesel engines, typically performed after ECM tuning for off-road or competition use.

Warnings

Tools required

Parts

• DPF delete pipe (4-inch straight-through) × 1 — Aftermarket 5.9L Cummins DPF delete pipe kit
• Exhaust gaskets (turbo-to-downpipe) × 2 — Use OEM specification or included in kit
• Exhaust flange gaskets × 2 — 3-inch or 4-inch depending on system
• Oxygen sensor bung plug (if not retaining sensors) × 1 — M18x1.5 stainless plug

Preparation

1. Park vehicle on level, solid ground and apply parking brake
2. Place wheel chocks behind rear wheels
3. Ensure exhaust system is completely cool to the touch
4. Spray all exhaust flange bolts, hanger bolts, and oxygen sensor threads with penetrating oil
5. Raise front of vehicle with floor jack and support securely on jack stands at frame rails behind front wheels
6. Raise rear of vehicle and support on jack stands if needed for clearance under entire exhaust path
7. Verify ECM has been tuned/programmed to disable DPF system or have tuning ready to install immediately after completion

Procedure

1. 1

   Disconnect oxygen sensors
   Locate the exhaust gas temperature (EGT) sensors and DPF differential pressure sensor/lines downstream of the turbocharger. Disconnect electrical connectors by pressing release tabs. Using an EGT sensor socket or appropriate wrench (verify size against the sensor hex), carefully unthread the EGT sensors from the exhaust pipes. If sensors will be reused, handle carefully to avoid damage to sensor tips. Apply penetrating oil and allow to soak if sensors are difficult to remove.
2. 2

   Remove heat shields
   Remove any exhaust heat shields covering the DPF assembly and surrounding exhaust components using 13mm socket. These shields are typically secured with multiple bolts to the frame or body. Set shields aside for reinstallation or disposal depending on delete pipe kit requirements.
   Torque spec

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

   Support DPF assembly
   Position a floor jack with wood block under the DPF canister to support its weight during removal. The DPF assembly is heavy and awkward; adequate support prevents damage to connected exhaust pipes when fasteners are loosened.
4. 4

   Disconnect exhaust hangers
   Locate rubber exhaust hangers supporting the DPF assembly and downstream exhaust. Remove hanger bolts using 15mm socket. There are typically 2-4 hangers depending on configuration. Note hanger positions for delete pipe installation. If hangers are seized to mounting points, carefully pry loose or cut rubber isolators.
   Torque spec

   Hanger Bolts20 Nm (15 lb-ft)
5. 5

   Remove upstream flange connection
   Locate the exhaust flange connecting the turbocharger downpipe or intermediate pipe to the DPF inlet. Remove flange bolts using 19mm socket. There are typically 2-3 bolts in this connection. Separate flange carefully; if seized, tap gently with rubber mallet. Lower jack slightly to create separation gap.
   ⚠Exhaust gases contain soot and particulate matter. Wear gloves and eye protection when separating exhaust connections.
   Torque spec

   Exhaust Flange Bolt45 Nm (33 lb-ft)
6. 6

   Remove downstream flange connection
   Locate the exhaust flange connecting the DPF outlet to the downstream exhaust pipe or muffler. Remove flange bolts using 19mm socket. Separate connection and lower DPF assembly on floor jack. If space is limited, may need to cut exhaust pipe with reciprocating saw downstream of DPF rather than disconnecting at flange.
   Torque spec

   Exhaust Flange Bolt45 Nm (33 lb-ft)
7. 7

   Remove DPF assembly
   With all connections separated and hangers disconnected, carefully lower DPF assembly on floor jack and remove from under vehicle. DPF assembly may weigh 40-60 lbs depending on configuration. Inspect all connection points for damage or excessive corrosion.
8. 8

   Clean mating surfaces
   Use wire brush to thoroughly clean all exhaust flange mating surfaces on both upstream and downstream pipes. Remove all old gasket material, carbon deposits, and corrosion. Surfaces must be flat and clean for proper sealing with new gaskets. Inspect flanges for warping or cracks.
9. 9

   Test fit delete pipe
   Position DPF delete pipe under vehicle and test fit alignment with upstream and downstream exhaust connections. Verify flange bolt holes align properly and pipe clears frame, crossmembers, driveshaft, and suspension components throughout full suspension travel. Adjust as needed before final installation.
10. 10

    Install oxygen sensor bungs or plugs
    If delete pipe includes provisions for oxygen sensors, install sensors in new locations applying anti-seize compound to threads only (avoid contaminating sensor tip). If EGT sensors are not being retained, install the correct bung plugs (verify thread size against the EGT sensor bungs, commonly M12x1.25 for diesel EGT sensors) with anti-seize compound. Torque EGT sensors or plugs to specification.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
11. 11

    Install upstream connection
    Position new exhaust gasket on upstream flange connection. Lift delete pipe into position using floor jack if needed. Align flange and start all bolts by hand. Apply anti-seize compound to bolt threads. Torque flange bolts in cross-pattern to specification. Do not fully tighten until downstream connection is also started.
    Torque spec

    Exhaust Flange Bolt45 Nm (33 lb-ft)
12. 12

    Install downstream connection
    Position new exhaust gasket on downstream flange connection. Align delete pipe outlet with downstream exhaust pipe and start all flange bolts by hand. Apply anti-seize compound to bolt threads. Verify delete pipe is properly positioned without stress or binding. Torque flange bolts in cross-pattern to specification.
    Torque spec

    Exhaust Flange Bolt45 Nm (33 lb-ft)
13. 13

    Install exhaust hangers
    Attach exhaust system to rubber hangers at all support points. Install and torque hanger bolts to specification. Ensure exhaust system hangs with adequate clearance from frame, body, driveshaft, and suspension components. Adjust hanger positions if needed to achieve proper clearance and prevent contact.
    Torque spec

    Hanger Bolts20 Nm (15 lb-ft)
14. 14

    Reconnect oxygen sensors
    Reconnect oxygen sensor electrical connectors ensuring positive engagement of locking tabs. Route wiring away from exhaust heat and moving components. Secure wiring with original clips or zip ties as needed.
15. 15

    Reinstall heat shields
    If retaining heat shields, reinstall over exhaust system using original mounting locations. Install and torque heat shield bolts to specification. Trim or modify shields as needed to clear modified exhaust routing.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Double-check all flange bolts are torqued to specification in cross-pattern
2. Verify oxygen sensor electrical connectors are fully seated and locked
3. Confirm exhaust system has minimum 1-inch clearance from all chassis, body, and driveline components
4. Verify exhaust hangers are properly seated and supporting system weight evenly

Verification

• Remove jack stands and carefully lower vehicle to ground
• Start engine and immediately check all exhaust connections for leaks (listen for hissing and look for visible exhaust escaping)
• Verify no check engine lights are present (requires ECM to be properly tuned for DPF delete)
• Allow engine to reach operating temperature and recheck all connections for leaks
• Test drive vehicle and verify no exhaust rattles, vibrations, or contact with chassis components
• Recheck all flange bolt torque after 50-100 miles of driving as exhaust gaskets may settle

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