6.7 Cummins Delete Kit: What Every Ram Owner Should Know About Emissions Systems
DPFexhaust Team | June 2026 | 8 min read
How the 6.7 Cummins Emissions System Differs From the 5.9 Cummins
The shift from the 5.9L Cummins (used through 2007 in Ram trucks) to the 6.7L Cummins (introduced mid-2007 as a 2007.5 model) brought one of the most significant changes in diesel truck emissions equipment.
The 5.9L Cummins ran with no emissions controls beyond basic crankcase ventilation. There was no Diesel Particulate Filter trapping soot from the exhaust stream, no DEF injection system dosing urea into a SCR catalyst, and no EGR cooler recirculating exhaust gas back through the intake manifold. The engine breathed clean air in and pushed raw exhaust out. It was simple, reliable, and entirely unregulated at the federal level during its production years.
The 6.7L Cummins arrived just as EPA 2007 diesel emissions standards took effect, and it carries three major emissions subsystems: a DPF (Diesel Particulate Filter) that captures soot and periodically burns it off through regeneration cycles; an EGR (Exhaust Gas Recirculation) system that routes cooled exhaust gas back into the intake to reduce combustion temperatures and NOx formation; and on 2013+ models, a DEF/SCR (Selective Catalytic Reduction) system that injects Diesel Exhaust Fluid to further reduce tailpipe NOx. Understanding this architectural difference explains why cummins delete kit searches have become so common among 6.7 owners -- they are dealing with complexity that earlier Cummins drivers never encountered.
Forum Discussions About 6.7 Cummins Emissions
The following threads represent some of the most frequently cited owner frustrations related to the 6.7 Cummins emissions systems:
Discussion 1 -- Frequent Regen Cycles After Sensor Replacement
A CumminsForum.com member reported that after having the particulate sensor replaced on their 6.7L Cummins, the truck began entering regeneration mode far more often than before -- approximately every 300 km. The dealer had already replaced the MAF (Mass Air Flow) sensor as part of the diagnosis, yet the frequent regen behavior persisted. When any sensor in the emissions chain gets replaced or recalibrated, the ECM may interpret soot loading data differently and trigger regen more aggressively as a precautionary measure.
"My cummins 6.7 had a particulate sensor replaced and since then I have been experiencing a regen about every 300 km. They replaced the MAF too but it's still doing it." -- CumminsForum.com member
Frequent active regen cycles burn additional fuel, raise under-hood temperatures, and over time, contribute to oil dilution. Owners who drive mostly short distances or idle heavily report this issue most often because the DPF never gets enough sustained highway heat to complete passive regeneration.
Discussion 2 -- Daily Regen and Oil Dilution Concerns
A 6.7 Cummins owner raised a concern shared by many in the community: their truck was initiating a full regeneration cycle every single day, and they wanted to understand whether this frequency would cause fuel contamination of the engine oil. The thread sparked considerable debate about acceptable oil level rise thresholds, how much diesel fuel typically enters the oil pan during each regen event, and whether shortened oil change intervals could fully address the risk.
"My 6.7 Cummins is having a daily regen. Do I need to worry about oil dilution? I'm checking my oil level every few days now." -- Bob Is The Oil Guy
Daily regen on a 6.7 Cummins is not normal factory behavior and usually indicates either a failing sensor, a partially clogged DPF that cannot passively regenerate, or driving patterns that prevent the system from completing passive soot oxidation. When owners encounter this pattern, the standard recommendation is to check soot load values with a diagnostic scanner, inspect the DPF pressure differential, and consider whether a long highway run can help clear accumulated soot.
Discussion 3 -- EGR Cooler Failure Causing Coolant Loss
A RamForumZ member documented a troubling sequence on their 2017 6.7L Cummins: the truck began losing coolant with no visible external leak. Diagnosis eventually revealed that the DPF had become restricted, creating excessive backpressure that forced exhaust gases backward through the EGR cooler. The internal cooler core cracked under the abnormal pressure differential, allowing exhaust gas to leak between the two circuits.
"DPF was restricted and backpressure was up. Exhaust was leaking into the cooling system from the EGR cooler. Did a manual regen and could see exhaust soot coming out the EGR cooler coolant ports." -- 2017 Ram 2500 owner
This failure mode deserves attention because it connects two seemingly separate problems -- a clogged DPF and a leaking EGR cooler -- into a single cascading failure chain. The EGR cooler on the 6.7 Cummins uses thin internal passages that are vulnerable to cracking when backpressure exceeds design limits, and once coolant enters the exhaust side, the repair scope expands dramatically from a simple DPF cleaning to a full cooler replacement plus cooling system flush.
Maintenance Solutions Without Replacing Factory Emissions
If your goal is to keep the stock emissions system intact and resolve recurring issues through proper care, the following steps address the most common failure modes on the 6.7 Cummins platform. Work through these systematically before considering any component replacement.
Step 1: Force a Parked Regeneration and Monitor Soot Levels
If your truck is entering active regen more frequently than usual or showing DPF-related warnings, start by using a diagnostic tool capable of triggering a parked (stationary) regeneration cycle. Let the process run to completion without interruption -- this typically takes 20 to 40 minutes depending on soot load. Afterward, check the DPF soot mass reading. If the value remains above 2.0 grams despite a completed regen, the filter itself may be nearing end-of-service life and need to be replaced.
Step 2: Clean or Replace the DPF Pressure Sensors
The two pressure sensors mounted before and after the DPF tell the ECM how much soot has accumulated based on the pressure drop across the filter element. When these sensors drift out of calibration or get coated with soot and oil residue, they report inaccurate data, causing premature regen triggers or missed regen events. Remove both sensors, clean them with electrical contact cleaner, inspect the wiring harness for chafing, and test voltage output against factory specs. On high-mileage 6.7 engines, replacing both sensors as a pair is often more economical than repeated troubleshooting.
Step 3: Inspect the EGR Cooler for Internal Leaks and External Blockage
EGR cooler failures on the 6.7 Cummins fall into two categories: internal cracks that allow coolant and exhaust to mix (visible as coolant loss with white exhaust smoke or coolant reservoir pressurization), and carbon blockage that restricts EGR flow and triggers fault codes. To check for internal leaks, pressurize the cooling system to specification and watch for bubbles in the coolant reservoir or pressure drop without an obvious external leak. For blockage concerns, remove the EGR tube connecting the cooler outlet to the intake and visually inspect the passage for heavy carbon buildup. A blocked cooler can sometimes be restored with a chemical cleaning procedure, but severely fouled units should be replaced rather than repeatedly cleaned.
Step 4: Service the DEF System and Check Injector Condition
On 2013+ 6.7 Cummins models, DEF system faults account for a large percentage of dashboard warnings and limp-mode events. Begin by checking DEF fluid quality -- crystallized deposits around the injector nozzle indicate either contaminated fluid or not atomizing injector. Run a DEF quality test with a supported scanner. If you live in a cold area, inspect the DEF tank heater operation, since frozen DEF will prevent the system from dosing and trigger a cascade of fault codes, including check-engine light and reduced-power messages. Replace the DEF filter every 40,000 to 50,000 miles as preventive maintenance.
Following these four steps resolves the majority of recurring emissions issues on stock 6.7 Cummins trucks without requiring any modification to the factory DPF, EGR, or DEF configuration. Clear all stored codes after each step and drive under conditions that previously triggered the problem to confirm the fix before proceeding to the next item.
6.7 Cummins Delete Kits: An Alternative Solution for Off-Road Use
For owners who operate their Ram trucks exclusively off-road, on private property, or for competition purposes, removing the factory DPF, DEF, and EGR hardware is an alternative solution worth considering. Below are the three primary 6.7 cummins delete kit configurations available at DPFexhaust.com, organized by tuner platform. Each package includes everything needed for a complete removal: the tuner device (with custom calibrations), DPF delete race pipe, EGR delete hardware, and DEF system bypass components if applicable.
DPF/DEF/EGR Delete Kit with EFI Live TunerEFI Live AutoCal V3
2013--2021 Ram 2500 / 3500 6.7L Cummins
- EFI Live AutoCal V3 tuner. We will email the custom tune file to you based on the vehicle info you submit
- Up to +130 HP gain and up to 18% improvement in fuel efficiency over stock tuning
- Shift-On-The-Fly (SOTF) tuning support on applicable model years for switching power levels while driving
- Multiple exhaust options available: 4-inch DPF Race pipe, 4-inch Turbo-Back exhaust, or 5-inch Turbo-Back exhaust configurations
- Complete EGR delete kit with aluminum intake bracket, O-rings, steel brackets, pyrometer plug, coolant adapter, and pre-molded coolant hose
DPF/DEF/EGR Delete Kit with Mini Maxx V2 TunerH&S Mini Maxx V2
2013--2018 Ram 2500 / 3500 6.7L Cummins
- H&S Mini Maxx V2 tuner with preloaded calibrations -- plug-and-play via OBDII port
- +80 to +150 HP and +150 to +250 lb-ft torque increase on stock turbo configuration
- Choice of EGR delete kit finish: Black, Red, or Silver to match under-hood aesthetics
- Five exhaust pipe configurations available including dual-exit 5-inch turbo-back exhaust option
- Eliminates DPF regeneration cycles completely, reducing exhaust gas temperatures and preventing oil dilution from regen fueling events
DPF/DEF/EGR Delete Kit with EZ Lynk TunerEZ Lynk AutoAgent 2.0
2013--2018 Ram 2500 / 3500 6.7L Cummins
- EZ Lynk AutoAgent 2.0 device with 60-second OBDII setup -- no ECM removal or swap required
- Cloud-based tune delivery with unlimited file access and over-the-air update capability through iOS or Android app
- SOTF (Shift-On-The-Fly) tune option provides five selectable power levels switchable from the driver seat
- Built-in real-time diagnostics, DTC read/clear functionality, and FMCSA-compliant ELD capability for fleet use
- Stops regeneration-induced oil dilution, prevents EGR soot buildup in intake ports, lowers sustained EGTs under load
Additional Year-Specific Cummins Delete Kits:
Each delete kit is a matched set of components designed for its specific engine generation and year range. Flashing an appropriate tune that disables emissions-system operation in the engine calibration must always be completed before physically removing any emissions hardware. For fitment questions, compatibility concerns, or guidance on selecting the correct kit for your vehicle, contact service@dpfexhaust.com before ordering -- the team typically responds within 24 hours.
