This procedure covers the replacement of a universal catalytic converter on a 2014 Ram 2500 with the 6.7L Cummins diesel engine, including removal of the factory catalytic converter and installation of a universal replacement unit.

Warnings

Tools required

Parts

• Universal catalytic converter (2.5" or 3" inlet/outlet, diesel rated) × 1 — Match diameter to factory exhaust pipe
• Exhaust flange gaskets × 2 — Use OEM specification
• Exhaust clamps or band clamps (if not welding) × 4 — 3" stainless steel exhaust clamps
• Oxygen sensor(s) × 1 — Reuse existing if in good condition
• Exhaust hangers/isolators × 2 — Replace if deteriorated
• Anti-seize compound (nickel-based) × 1 — High-temperature rated
• Exhaust sealant (if using clamps) × 1 — High-temperature exhaust paste

Preparation

1. Park vehicle on level ground and allow exhaust system to cool completely (minimum 2 hours after last operation)
2. Engage parking brake and chock rear wheels securely
3. Raise front of vehicle using floor jack and support with heavy-duty jack stands rated for vehicle weight (approximately 7,000 lbs)
4. Spray all exhaust flange bolts, oxygen sensor threads, and hanger bolts with penetrating oil and allow to soak for 15-30 minutes
5. Disconnect negative battery terminal to prevent oxygen sensor fault codes during removal
6. Locate catalytic converter in exhaust system (positioned between turbocharger outlet and DPF on 6.7L Cummins)
7. Measure and photograph exhaust system configuration for reference during universal converter installation

Procedure

1. 1

   Remove oxygen sensor(s)
   Disconnect oxygen sensor electrical connector(s) by pressing release tab and pulling connector apart. Using a 22mm oxygen sensor socket, carefully unthread the oxygen sensor(s) from the catalytic converter or adjacent exhaust pipe. Turn counterclockwise slowly to avoid breaking sensor. Inspect sensor threads and tip condition; replace if damaged or contaminated with carbon buildup.
   ⚠Oxygen sensors are fragile. Do not drop or impact sensor as this will damage the internal element.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
2. 2

   Remove heat shields
   If present, remove any heat shields covering the catalytic converter area. Remove heat shield mounting bolts using appropriate socket. Set heat shields aside for reinstallation or replacement.
   Torque spec

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

   Disconnect upstream exhaust flange
   Locate the upstream exhaust flange connecting the catalytic converter to the turbocharger downpipe or intermediate pipe. Remove the flange bolts using appropriate socket while supporting the exhaust pipe to prevent stress on other components. Separate flange connection and remove old gasket material with wire brush.
   ⚠Bolts may be corroded and brittle. Apply additional penetrating oil if resistance is encountered. Replacing corroded bolts is recommended.
   Torque spec

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

   Disconnect downstream exhaust connection
   Locate the downstream connection between catalytic converter and DPF or intermediate pipe. If flanged connection, remove flange bolts and separate. If welded or clamped connection, this will be cut in the next step. Support exhaust system weight with jack stand or helper.
   Torque spec

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

   Remove exhaust hangers
   Locate rubber exhaust hangers supporting the catalytic converter section. Remove hanger bolts if bolted type, or use exhaust hanger removal tool to slide rubber isolators off hanger hooks. Note hanger positions for reinstallation.
   Torque spec

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

   Remove factory catalytic converter
   If the catalytic converter is welded into the exhaust system, use an angle grinder with cutoff wheel or reciprocating saw with metal blade to cut the exhaust pipe on both sides of the catalytic converter. Make cuts as straight as possible approximately 2-3 inches from each end of the converter housing. Ensure adequate clearance from fuel lines, wiring, and brake lines. Remove the factory catalytic converter from vehicle. Clean cut edges with wire brush or grinder to create smooth mating surface.
   ⚠️Flying sparks and metal fragments pose fire and injury risk. Clear all flammable materials from work area. Have fire extinguisher accessible.
   ⚠Verify location of fuel lines, brake lines, and wiring harnesses before cutting. Damage to these components can result in dangerous failures.
7. 7

   Measure and prepare universal catalytic converter
   Measure the distance between the two cut points in the exhaust system. Measure the universal catalytic converter total length including inlet and outlet pipes. The universal converter should fit with approximately 2-3 inches of overlap on each connection point. If necessary, trim the universal converter's inlet or outlet pipes to achieve proper fit. Ensure inlet and outlet pipe diameters match the factory exhaust pipes (typically 3 inches on 6.7L Cummins). Test fit the universal converter in position before final installation.
   ℹ️Universal converters may require custom fitting. Ensure adequate clearance from chassis, fuel tank, driveshaft, and suspension components with at least 1 inch minimum clearance.
8. 8

   Install universal catalytic converter
   Position universal catalytic converter into exhaust system with proper flow direction (arrow on converter body indicates exhaust flow direction toward rear of vehicle). Slide universal converter pipes into or over factory exhaust pipes with 2-3 inch overlap on each end. Align converter to maintain proper ground clearance and avoid contact with chassis or suspension. If welding, tack weld in 3-4 spots to hold position. If using clamps, position clamps over joints but do not tighten yet.
   ⚠Ensure catalytic converter arrow indicating flow direction points toward rear of vehicle. Incorrect installation will cause exhaust backpressure and engine performance issues.
9. 9

   Secure exhaust connections
   If welding: Perform complete weld around both pipe joints using MIG welder with exhaust-rated wire. Create continuous, leak-free welds. Allow welds to cool. If using clamps: Apply high-temperature exhaust sealant to pipe joints. Position band clamps or exhaust clamps over each joint and tighten securely per clamp manufacturer specifications (typically 40-60 lb-ft for band clamps). Use minimum of two clamps per connection point for secure installation.
   ℹ️Welded connections are preferred for longevity and leak prevention. Clamped connections may require periodic retightening.
10. 10

    Reinstall oxygen sensor(s)
    Apply a thin coat of nickel-based anti-seize compound to oxygen sensor threads only (do not get anti-seize on sensor tip). Thread oxygen sensor(s) into catalytic converter or exhaust pipe bung by hand until finger-tight. Using oxygen sensor socket and torque wrench, tighten to specification. Reconnect oxygen sensor electrical connector(s) ensuring positive lock engagement.
    ⚠Never apply anti-seize to oxygen sensor tip. Contamination of sensor element will cause false readings and check engine light.
    Torque spec

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

    Reinstall exhaust hangers
    Reinstall rubber exhaust hangers onto hanger hooks or reinstall hanger bolts. Ensure exhaust system is properly supported and positioned with adequate clearance from all chassis components, suspension, driveshaft, and fuel system. Adjust hanger positions if needed to achieve proper alignment.
    Torque spec

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

    Reinstall heat shields
    If heat shields were removed, reinstall them in original positions using heat shield bolts. Ensure heat shields do not contact catalytic converter housing directly and maintain proper clearance.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
13. 13

    Reconnect battery and clear codes
    Reconnect negative battery terminal. If vehicle is equipped with a diagnostic scan tool, clear any oxygen sensor or catalytic converter efficiency codes that may have been stored during the repair. This allows the system to start fresh monitoring with the new catalytic converter.

Reassembly

1. Verify all exhaust connections are secure with no gaps or misalignment
2. Ensure minimum 1 inch clearance between exhaust system and all chassis components, fuel lines, brake lines, wiring, suspension components, and driveshaft
3. Check that all oxygen sensor electrical connections are properly seated and locked
4. Verify exhaust hangers are properly positioned and supporting system weight evenly

Verification

• Start engine and listen for exhaust leaks at all connection points. A hissing sound indicates a leak requiring correction
• Allow engine to reach operating temperature and verify no unusual odors or smoke from exhaust system
• Check for exhaust leaks using soapy water solution applied to all joints while engine is running at idle (bubbles indicate leak)
• Perform visual inspection under vehicle with engine running to verify no contact between exhaust and chassis components
• Test drive vehicle and monitor for check engine light. Oxygen sensor codes may take 1-2 drive cycles to clear as system relearns
• After 50-100 miles of driving, re-inspect all clamp connections (if used) and retighten if necessary
• Verify catalytic converter efficiency is within acceptable parameters using OBD-II scanner after 2-3 complete drive cycles

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