Author: John Lee, SPELAB Mechanical Engineer. Updated on May 12, 2026.
Quick Answer: What Should You Know Before Removing the DPF and EGR on a 6.7 Cummins?
A 6.7 Cummins DPF and EGR delete is an off-road or competition-use modification that removes or bypasses factory emissions components such as the Diesel Particulate Filter and Exhaust Gas Recirculation system. Owners usually consider it because of repeated regeneration problems, DPF clogging, EGR soot buildup, limp mode, exhaust restriction, or intake contamination.
Important compliance note: Removing or disabling DPF, EGR, DEF, SCR, CAT, or other emissions equipment from a public-road vehicle may violate emissions laws and may fail inspection. This guide is written for off-road, competition, or non-public-road applications where such modifications are legally allowed. Always check federal, state, and local rules before modifying a truck.
For off-road builds, the hardware is only one part of the job. You must plan the correct DPF delete pipe, EGR delete kit, sensor handling, exhaust fitment, coolant routing, and tuning strategy before removing parts.
Why 6.7 Cummins Owners Consider DPF and EGR Delete
The factory DPF and EGR systems exist to reduce emissions. The DPF captures soot and burns it during regeneration. The EGR system routes part of the exhaust gas back into the intake to reduce combustion temperatures and NOx emissions.
From a diesel owner’s point of view, the common complaints are different: frequent regen cycles, limp mode, soot buildup in the intake, restricted exhaust flow, EGR cooler issues, and expensive emissions-related repairs. That is why some off-road 6.7 Cummins owners compare delete kits.
| Owner Concern | Stock System Behavior | What an Off-Road Delete May Change |
|---|---|---|
| Frequent regen | DPF burns accumulated soot during regeneration cycles | Removes DPF regen events on off-road-use setups |
| Limp mode | Sensor faults or high soot load may trigger reduced power | Correct tuning and diagnostics are required to avoid new fault behavior |
| EGR soot buildup | Soot can re-enter the intake path through EGR flow | May reduce EGR-related soot entering the intake where legally allowed |
| High exhaust restriction | Restricted DPF can increase backpressure | May reduce restriction with a proper off-road pipe |
| Fuel economy | Regen and restriction may affect MPG | Some owners report gains, but results depend heavily on tune and use |
For a broader explanation, read what a DPF delete does to your truck.
Stock vs Off-Road Deleted 6.7 Cummins: Realistic Comparison
The table below is not a guaranteed performance claim. Real-world results depend on model year, tuning, tire size, gearing, load, driving style, altitude, exhaust layout, turbo health, injector condition, and maintenance history.
| Category | Stock Emissions System | Off-Road Deleted Setup | Reality Check |
|---|---|---|---|
| EGT | Can rise during regeneration and heavy load | May reduce regen-related heat events | Towing and poor tuning can still create high EGT |
| MPG | Can be affected by regen, restriction, and driving pattern | Some owners report better fuel economy | No fixed MPG gain is guaranteed |
| Intake cleanliness | EGR can contribute to soot buildup | May reduce EGR-related soot entry | Oil vapor from CCV can still create residue |
| Power | Factory calibration prioritizes emissions compliance | Power depends mostly on tuning, not just hardware | Hardware alone does not guarantee horsepower |
| Legal status | Designed for public-road emissions compliance | Off-road or competition use only where legally allowed | Street use may violate emissions laws |
Critical: Tuning and Limp Mode Come Before Hardware Removal
Removing the DPF or EGR hardware without a proper plan for calibration can create check engine lights, limp mode, sensor faults, poor drivability, and failed readiness checks. On modern diesel trucks, the ECU expects signals from emissions components and sensors. If those systems are missing or changed, the truck may not operate normally.
Do not treat this as a simple pipe swap. Before removing hardware, confirm whether your off-road build has legal use approval, the correct parts, the correct calibration strategy, and a post-install scan plan.
| Without Proper Planning | Possible Result |
|---|---|
| DPF section removed but sensors not addressed correctly | Check engine light, derate, or limp mode |
| EGR removed without matching calibration | EGR-related fault codes or poor drivability |
| Coolant lines routed incorrectly after EGR cooler removal | Coolant leaks, overheating, or trapped air |
| Incorrect pipe length or cab configuration | Poor fitment, exhaust leak, or hanger misalignment |
For cost planning, read how much a DPF delete costs.
DPF Delete vs EGR Delete: What Is the Difference?
A DPF delete and an EGR delete affect different parts of the truck. Many owners discuss them together, but they are not the same job.
| Modification | Area Affected | What Usually Changes |
|---|---|---|
| DPF delete | Exhaust system | DPF section is replaced with an off-road pipe or exhaust section |
| EGR delete | Intake and exhaust gas recirculation path | EGR cooler, valve, or related tubes may be removed or blocked depending on kit |
| All-in-one delete kit | Exhaust, EGR, and tuning package | Combines hardware and tuning support for off-road builds |
If you are not sure which path fits your truck, compare an all-in-one 6.7 Cummins delete kit instead of buying separate parts blindly.
Parts Needed for a 6.7 Cummins DPF and EGR Delete
The exact parts depend on model year, cab configuration, emissions layout, pipe length, and whether the truck is used in an off-road or competition setting. Do not assume every 6.7 Cummins uses the same pipe or sensor layout.
- DPF delete pipe or off-road exhaust section
- EGR delete kit
- Model-year-specific tuning or calibration support for legal off-road use
- New gaskets, clamps, O-rings, and block-off plates as required
- Coolant plugs or hose routing parts if the EGR cooler is removed
- Replacement hardware for rusty or seized bolts
- Scan tool for code reading and post-install checks
For 2013–2018 Ram 2500/3500 owners, compare the specific 2013–2018 6.7 Cummins DPF delete pipe before ordering. Fitment matters.
Tools You Need for the Job
Your original article listed basic sockets, a torque wrench, drain pan, gloves, and eye protection. That is a good start. For a cleaner job, prepare the tools before opening the exhaust or coolant system.
- 10mm, 13mm, and 14mm sockets
- 5mm socket or Allen tool where required by clamps or brackets
- Ratchet and extensions
- Torque wrench
- Socket set and wrench set
- Pliers and hose clamp pliers
- Flathead and Phillips screwdrivers
- Drain pan for coolant if EGR cooler lines are opened
- Penetrating oil for rusted exhaust hardware
- Disposable gloves and eye protection
- Label tape or marker for sensors and connectors
- OBD scan tool for post-install diagnostics
Pre-Job Setup and Real-World Tips
The most frustrating part of a 6.7 Cummins DPF or EGR job is usually not the pipe itself. It is rusty fasteners, seized sensors, tight access near the firewall, and wiring or coolant routing mistakes.
- Let the exhaust and engine cool completely before touching pipes, sensors, or EGR parts.
- Spray penetrating oil on exhaust clamps, EGR tube bolts, and sensor fittings the day before the job if rust is present.
- Take photos before removing brackets, tubes, wires, or coolant hoses.
- Label EGT sensors, pressure lines, NOx/O2-related connectors where equipped, and harness clips.
- Keep coolant away from connectors and belts if EGR cooler lines are opened.
- Support heavy exhaust sections before loosening hangers or clamps.
- Keep the intake and coolant system clean. Dirt inside the system can create problems later.
John Lee’s field note: On older trucks, the bolt near the firewall is often the one that turns a simple job into a long afternoon. Penetrating oil, patience, and the correct extension can save you from breaking hardware.
High-Level DPF Removal Planning for Off-Road Builds
The exact DPF removal process varies by model year and exhaust layout. Use the following as a planning overview, not a substitute for the instructions included with your kit.
Step 1: Access the Work Area
On some Ram 6.7 Cummins trucks, removing the driver-side inner fender liner improves access to engine bay fasteners, sensors, and related components. Keep clips and bolts organized.
Step 2: Label Sensors and Pressure Lines
Before removing the DPF section, label EGT sensors, DPF pressure tubes, and harness clips. Do not twist sensor wires. If a sensor is seized, use penetrating oil and the correct sensor socket.
Step 3: Support the Exhaust Section
The DPF section can be heavy. Support the exhaust before removing clamps or hangers. Do not let the pipe hang from one bracket or sensor wire.
Step 4: Replace the DPF Section with the Correct Off-Road Pipe
Install the correct off-road exhaust pipe for the truck’s year, cab, bed, and exhaust layout. Make sure the pipe clears the frame, driveline, wiring, and heat-sensitive components.
Step 5: Check for Exhaust Leaks
After installation, check every clamp and joint for leaks. A leak near the turbo, downpipe, or sensor area can cause noise, soot marks, or confusing sensor behavior.
High-Level EGR Removal Planning for Off-Road Builds
The EGR job is usually more involved than the DPF pipe because it can involve the intake path, coolant routing, EGR cooler, EGR valve, block-off plates, and electrical connectors.
Step 1: Drain Coolant if Required
If the EGR cooler or coolant lines are being removed, drain enough coolant into a clean drain pan. Keep coolant away from belts, connectors, and open intake areas.
Step 2: Remove Intake Components Blocking Access
Remove the intake tube or intake horn components required for access. Cover open intake areas immediately to prevent debris from entering the engine.
Step 3: Disconnect EGR Tubes and Related Hardware
The EGR tube connects the exhaust/EGR path to the intake side. Remove the required bolts and gaskets carefully. Replace damaged O-rings or crushed gaskets instead of reusing them.
Step 4: Install Block-Off Plates and Route Coolant Correctly
Install block-off plates, gaskets, coolant plugs, or reroute hoses as instructed. Tighten evenly and recheck coolant level after the first heat cycle.
Step 5: Confirm There Are No Coolant or Intake Leaks
After the truck reaches operating temperature, inspect coolant routing, hose clamps, and intake connections. Recheck after the first drive.
If you are focused on the intake side, compare the proper 6.7 Cummins EGR delete kit before disassembly.
Common Mistakes to Avoid
| Mistake | Why It Matters | How to Avoid It |
|---|---|---|
| Removing parts before confirming tuning | Truck may not run correctly or may enter limp mode | Confirm calibration support before hardware removal |
| Mixing up sensors | Can cause codes or incorrect readings | Label every connector and take photos |
| Breaking seized exhaust sensors | Sensors can be expensive and hard to remove | Use penetrating oil and proper sensor tools |
| Ignoring coolant routing | Can cause leaks or overheating after EGR removal | Follow the hose routing in the kit instructions |
| Leaving exhaust leaks | Can cause soot marks, noise, and poor sensor behavior | Check all clamps after installation |
| Assuming every 6.7 Cummins uses the same pipe | Cab, bed, year, and chassis layout affect fitment | Confirm exact fitment before ordering |
Post-Installation Checklist
After any DPF or EGR delete work on an off-road 6.7 Cummins, do not assume the job is finished until the truck is checked mechanically and electronically.
- Confirm every exhaust clamp is tight and properly aligned.
- Check for exhaust leaks at every joint.
- Refill and bleed coolant if EGR coolant lines were opened.
- Verify intake boots and clamps are secure.
- Confirm no tools, rags, or debris are left in the engine bay.
- Reconnect batteries and check for warning lights.
- Scan for codes after first startup.
- Check for coolant leaks after the first heat cycle.
- Monitor EGT, boost, coolant temperature, and oil temperature during the first drive.
Should You Delete Both DPF and EGR Together?
Some off-road builds remove both systems together because DPF and EGR behavior are connected through tuning, airflow, exhaust temperature, and emissions strategy. However, deleting both systems increases legal, diagnostic, and tuning complexity.
| Setup | Best For | Things to Consider |
|---|---|---|
| DPF only | Exhaust-side off-road builds | May still have EGR soot and tuning questions |
| EGR only | Intake-side soot reduction where legally allowed | May not solve DPF restriction or regen concerns |
| DPF + EGR | Complete off-road delete builds | Requires correct tuning, parts, and legal-use confirmation |
| All-in-one kit | Owners wanting matched parts | Verify year, cab, pipe length, and tuning support |
For a complete matched package, compare the 6.7 Cummins all-in-one delete kit options. For buying guidance, see what is the best delete kit for 6.7 Cummins.
Expected Results and Realistic Limits
Many owners report stronger throttle response, fewer regen interruptions, lower exhaust restriction, and improved fuel economy after off-road DPF and EGR deletes. However, results are not guaranteed.
Final results depend on truck condition, tuning quality, tire size, gearing, driving style, fuel quality, turbo health, injector health, and whether the installation has exhaust or coolant leaks.
| Claim | Reality |
|---|---|
| More horsepower | Possible with correct tuning, but not guaranteed by hardware alone |
| Better MPG | Often reported by owners, but depends heavily on tune and driving style |
| No more emissions problems | Removes some systems but can create legal, tuning, or diagnostic issues |
| Easy DIY job | Possible for experienced owners, but seized sensors, coolant routing, and tuning can complicate the job |
Final Recommendation
A 6.7 Cummins DPF and EGR delete should not be treated as a casual weekend modification for a street-driven truck. It is an off-road or competition-use change that requires correct parts, correct tuning, clean mechanical work, and awareness of legal consequences.
If your truck is used on public roads or must pass emissions inspection, repairing the factory system may be the safer path. If your truck is an off-road build and deletes are legal for your use case, plan the job carefully: confirm fitment, label sensors, handle coolant correctly, install the right pipe and EGR parts, and scan the truck after startup.
FAQ
Q: Is it legal to delete the DPF and EGR on a 6.7 Cummins?
A: In many places, removing DPF or EGR equipment from a public-road vehicle is illegal and may fail inspection. Delete parts should only be used in off-road, competition, or non-public-road applications where legally allowed.
Q: What happens if you delete EGR and DPF?
A: On an off-road build with correct tuning, deleting EGR and DPF can reduce soot buildup, remove regen events, and lower exhaust restriction. It can also increase emissions, create legal risk, and require careful tuning and monitoring.
Q: Do you need tuning for a 6.7 Cummins DPF delete?
A: Yes, calibration planning is one of the most important parts of an off-road DPF delete build. Removing hardware without proper tuning support can trigger codes, limp mode, poor drivability, or readiness issues.
Q: Can you delete EGR without deleting DPF?
A: It may be possible depending on the truck and tuning strategy, but EGR and DPF behavior are connected through emissions logic. Always confirm compatibility before deleting one system and leaving the other in place.
Q: Can you delete DPF without deleting EGR?
A: Some off-road builds focus on the exhaust side first, but leaving EGR active may still create soot in the intake path. The correct choice depends on the truck, tune, and legal use case.
Q: How much horsepower does a DPF and EGR delete add?
A: Hardware alone does not guarantee horsepower. Power changes depend mainly on tuning, turbo health, fuel system condition, airflow, and supporting modifications.
Q: How much does it cost to delete EGR and DPF on a 6.7 Cummins?
A: Cost depends on parts, pipe layout, EGR kit, tuning, labor, and model year. Many complete jobs range from budget DIY parts to several thousand dollars when tuning and labor are included.
Q: Will a deleted 6.7 Cummins pass inspection?
A: In many emissions-regulated areas, no. A deleted truck may fail visual inspection, OBD readiness checks, or emissions testing.
Q: Can you reverse a DPF delete?
A: In many cases, yes, if you kept the original parts and the truck can be returned to factory calibration. Reversal may require original emissions hardware, sensors, exhaust sections, and ECU programming.
Q: What is the biggest mistake during a DPF or EGR delete?
A: Removing emissions parts before confirming tuning and legal use. Other common mistakes include mixing up sensors, breaking seized exhaust sensors, leaving coolant leaks, and failing to check for exhaust leaks after installation.
Q: Should I choose separate parts or an all-in-one kit?
A: An all-in-one kit can simplify parts matching if it is designed for your exact truck year and configuration. Separate parts may work, but fitment, pipe length, tuning, and sensor handling must all be verified.
John Lee
Mechanical Engineer | 10+ Years Experience
John has spent the last decade engineering and testing high-performance automotive components. Specializing in drivetrain durability and thermal management across Powerstroke, Cummins, and Duramax applications, he bridges the gap between OEM limitations and aftermarket performance. His philosophy: "Factory parts are just a starting point."
2 comments
Are you referencing the 6.7 Cummins diesel on Ram Trucks? There is no turbo y-bridge, only 1 turbo, only 1 valve cover, and only 1 downpipe. Also, when you refer to the mudflap are you meaning the inner fender liner? This makes it very confusing for a DIY’er such as myself.
Don’t you need a timer to disconnect these two things