This procedure covers the removal and replacement of the California emissions-compliant catalytic converter on a 2014 Ram 2500 with the 6.7L Cummins diesel engine.

Warnings

Tools required

Parts

• Catalytic converter assembly (California emissions) × 1 — Use OEM specification for CARB compliance
• Exhaust flange gaskets × 2 — Use OEM specification
• Exhaust hanger isolators (if damaged) × 1 — Inspect and replace as needed

Preparation

1. Ensure engine and exhaust system are completely cold to the touch
2. Park vehicle on level ground and set parking brake
3. Place wheel chocks behind rear wheels
4. Disconnect negative battery cable to prevent electrical issues
5. Raise vehicle using appropriate jack points and support securely on jack stands rated for vehicle weight
6. Spray all exhaust flange bolts, hanger bolts, and O2 sensor threads with penetrating oil and allow to soak for 15-30 minutes

Procedure

1. 1

   Remove heat shields
   Locate and remove any heat shields covering the catalytic converter area. Remove heat shield mounting bolts and carefully set shields aside. Inspect heat shields for damage and replace if cracked or severely corroded.
   Torque spec

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

   Disconnect oxygen sensors
   Locate the upstream and downstream oxygen sensors on the catalytic converter. Disconnect the electrical connectors by pressing the release tab and pulling apart. Using an oxygen sensor socket, carefully unthread each sensor by turning counterclockwise. Note the position and orientation of each sensor for proper reinstallation.
   ⚠O2 sensors are fragile. Do not drop or impact sensors as this will damage the internal element and require replacement.
   Torque spec

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

   Disconnect upstream exhaust flange
   Locate the flange connection between the turbocharger outlet or DPF and the catalytic converter inlet. Remove the flange bolts using appropriate socket. If bolts are seized, apply additional penetrating oil and use a breaker bar. Remove and discard the old flange gasket.
   ⚠If bolts break during removal, the remaining stud must be extracted or the flange may need replacement. Work carefully to avoid damage.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
4. 4

   Disconnect downstream exhaust flange
   Locate the flange connection between the catalytic converter outlet and the downstream exhaust pipe. Remove all flange bolts and separate the connection. Remove and discard the old flange gasket. You may need to use a pry bar to gently separate the flanges if they are stuck together.
   Torque spec

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

   Remove exhaust hangers
   Locate all rubber exhaust hangers supporting the catalytic converter assembly. Remove hanger bolts or use a pry bar to carefully disconnect the hangers from their mounts. Inspect rubber isolators for cracking or deterioration and replace if necessary.
   Torque spec

   Hanger Bolts27 Nm (20 lb-ft)
6. 6

   Remove catalytic converter
   With all connections and hangers disconnected, carefully lower and remove the catalytic converter assembly from the vehicle. The converter is heavy, so support it properly to prevent dropping. Inspect all mounting points and surrounding components for damage or excessive corrosion.
   ⚠Catalytic converter assembly is heavy and awkward to handle. Use a second person or proper support to prevent injury or component damage.
7. 7

   Prepare installation surfaces
   Use a wire brush to thoroughly clean all flange mating surfaces, removing old gasket material, rust, and carbon deposits. Clean oxygen sensor bungs in the new catalytic converter if necessary. Ensure all surfaces are clean and flat for proper sealing.
8. 8

   Install new catalytic converter
   Position the new California emissions-compliant catalytic converter into place, aligning with upstream and downstream flanges. Install exhaust hangers loosely to support the assembly but allow for adjustment. Ensure proper orientation with O2 sensor bungs accessible and not contacting frame or body components.
9. 9

   Install upstream flange connection
   Install new flange gasket onto upstream flange. Apply anti-seize compound to exhaust flange bolt threads. Insert bolts and hand-tighten. Torque bolts in a cross-pattern to specified torque value to ensure even gasket compression and prevent exhaust leaks.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
10. 10

    Install downstream flange connection
    Install new flange gasket onto downstream flange. Apply anti-seize compound to flange bolt threads. Insert bolts and hand-tighten. Torque bolts in a cross-pattern to specified torque value. Verify the entire exhaust system is properly aligned before final tightening.
    Torque spec

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

    Secure exhaust hangers
    With flanges secured and exhaust properly aligned, tighten all exhaust hanger bolts to specified torque. Ensure catalytic converter has adequate clearance from frame, driveshaft, fuel lines, and brake lines throughout full suspension travel.
    Torque spec

    Hanger Bolts27 Nm (20 lb-ft)
12. 12

    Install oxygen sensors
    Apply a thin coat of anti-seize compound to the threads of each oxygen sensor (avoid getting anti-seize on the sensor tip). Thread each sensor by hand into the correct bung location (upstream and downstream). Tighten to specified torque using oxygen sensor socket. Reconnect electrical connectors ensuring they click into place securely.
    ⚠Only apply anti-seize to sensor threads. Any anti-seize on the sensor element will contaminate it and cause false readings.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
13. 13

    Reinstall heat shields
    Position heat shields over the catalytic converter assembly. Install heat shield bolts and tighten to specified torque. Ensure heat shields do not contact the converter directly and have proper clearance to prevent rattling.
    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 underneath vehicle to verify all connections are secure and no tools were left behind
4. Check that all electrical connectors for oxygen sensors are properly seated

Verification

• Start engine and allow to idle. Listen for any exhaust leaks at flange connections (hissing or ticking sounds indicate leaks)
• Visually inspect all flange connections while engine is running for evidence of exhaust gas escaping
• Rev engine slightly and verify no abnormal vibrations or rattling from exhaust system
• Allow engine to reach operating temperature and verify no warning lights on dashboard related to oxygen sensors or emissions system
• Use scan tool to check for any diagnostic trouble codes related to catalytic converter efficiency or oxygen sensor operation
• Verify catalytic converter has proper clearance from all components during engine torque movement
• Test drive vehicle and verify normal operation with no exhaust odors in cabin and proper engine performance

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