Contents
Contents
- What Is a DEF Delete Kit for 6.7 Cummins?
- Can You Delete DEF Without Touching DPF and EGR?
- Which Product Should You Buy for a 6.7 Cummins DEF Delete?
- How Much Does It Cost to Delete DEF on 6.7 Cummins?
- Legal and Environmental Risks Specific to DEF Delete
- Should You Delete DEF on Your 6.7 Cummins?
- FAQs
If you own a 6.7 Cummins diesel truck, you may have already noticed that regularly adding diesel exhaust fluid (DEF) is not only an extra expense, but the SCR system can also fail at any time and leave you stranded. As a result, more and more truck owners have started looking into "DEF delete." This article will walk you through everything you need to know: what a 6.7 Cummins DEF delete kit is, why owners consider it, how it works, the best kit recommendation, cost breakdown, and all the risks you need to understand.
📌 Important Note: This article specifically focuses on deleting the DEF (Diesel Exhaust Fluid) system. If you are looking for a complete DPF/DEF/EGR full delete kit recommendation and installation guide, please see our related article: Best 6.7 Cummins Delete Kits 2026. This article will not repeat the full kit list. Instead, it focuses on DEF-specific pain points, misconceptions, costs, and risks.
What Is a DEF Delete Kit for 6.7 Cummins?
A "DEF delete kit for 6.7 Cummins" refers to a modification solution designed to remove or bypass the DEF/SCR system on a 6.7L Cummins diesel engine. Its core purpose is to remove or bypass the SCR (Selective Catalytic Reduction) system—the part that requires you to regularly refill DEF.
A modern 6.7 Cummins diesel emissions system includes three major components: the DPF (Diesel Particulate Filter), EGR (Exhaust Gas Recirculation) system, and SCR/DEF system. A DEF delete kit is aimed specifically at the SCR/DEF portion of that emissions system.
When you search for a "DEF delete kit," you might imagine a standalone hardware box that simply plugs in and disables DEF injection. In reality, it is much more complicated. Most "DEF delete kits" are actually full emissions delete solutions that handle EGR, DPF, and DEF together. There are generally no mainstream retail products that only delete DEF as a standalone system.
Can You Delete DEF Without Touching DPF and EGR?
Let's answer one of the most common questions directly: technically, yes; practically, it is not recommended.
From a technical standpoint, you would only need an ECU tuning file that supports DEF disabling and an SCR simulator. This would allow you to keep the DPF and EGR in place and continue driving. But why do very few people do this?
The DPF Can Clog Quickly
Most DEF-disable tunes also turn off DPF regeneration logic because tuners usually assume you are removing the DPF as well. If you keep the DPF but regeneration is disabled, soot can build up quickly and clog the DPF within a few hundred miles.
The EGR Still Works
The EGR system sends soot-containing exhaust gases back into the intake manifold, which can contaminate the intake system over time. Keeping the EGR while deleting DEF does not solve the side effects caused by EGR operation.
There Is No Standalone Product
You will rarely find a retail product called a "DEF-only delete kit." Mainstream brands, including SuncentAuto, generally sell full delete kits rather than DEF-only kits.
Conclusion: If you are dealing with DEF system problems but do not plan to remove the DPF and EGR, the better choice is to repair the DEF system itself—clean the injector, replace sensors, or use high-quality DEF—instead of attempting an incomplete delete.
Which Product Should You Buy for a 6.7 Cummins DEF Delete?
As explained above, there is generally no standalone kit that only removes the DEF system. The most reliable way to permanently eliminate DEF-related problems is to remove the DPF/DEF/EGR/CCV systems completely, which is usually sold as an all-in-one full delete kit.
✅ Recommended: Suncent All-in-One Delete Kit for 2013–2018 6.7L Cummins
If you own a 2013–2018 Dodge/Ram 2500 or 3500 equipped with a 6.7L Cummins engine and you have decided to perform a full delete for off-road or race-use applications, we recommend the Suncent DPF/DEF/EGR/CCV All-in-One Delete Kit. This kit includes the major components you need in a single purchase.
What the Kit Includes
| Component | Details |
| ECU Tuner | Mini Maxx Tuner V2 — preloaded with delete maps designed to disable DEF, DPF regeneration, and EGR logic |
| Delete Pipe | 4-inch turbo-back race pipe without muffler — physically replaces DPF and SCR/DEF hardware |
| EGR Delete Kit | EGR valve and cooler delete kit with throttle valve delete — includes block-off plates and coolant bypass hose |
| CCV Reroute Kit | PCV/CCV crankcase ventilation reroute filter kit |
| Hardware | Includes clamps, brackets, and gaskets for installation |
Real-World Performance Benefits
Better fuel economy: May improve fuel efficiency, especially under load.
Improved engine performance: Helps improve throttle response and overall power output.
Lower maintenance costs: Eliminates costly DPF replacement and DEF system repairs.
Lower engine temperatures: Bypassing the EGR system may help the engine run cooler and extend the life of key engine components.
Longer system life: Less stress on the cooling and exhaust systems may mean fewer long-term repairs.
For other products and years, please see our full product list: 6.7L Cummins Delete Kit
✅ Why Choose SuncentAuto?
SuncentAuto has become a well-known brand in the field of diesel truck performance modification, possessing IATF-16949 certified production facilities and a professional R&D team. The company has warehouses in the United States, ensuring fast and free delivery throughout the country. All orders enjoy a 45-day hassle-free return policy and dedicated customer support, typically responding within 24 hours.
Exclusive reader discount code: BLOG12
Full coupon page: SuncentAuto Discounts and Codes
How Much Does It Cost to Delete DEF on 6.7 Cummins?
Because you generally cannot delete only the DEF system in real-world applications, the following costs are estimates for a full system delete, including DPF, DEF, and EGR, with a focus on DEF-related expenses.
| Item | Cost Range | Notes |
| Tuning Device, such as Mini Maxx or EZ Lynk | $400–$900 | One-time purchase |
| Full Delete Tune, including DEF disable | $150–$500 | Sometimes bundled with the tuning device |
| DPF/DEF Delete Exhaust Pipe | $600–$1,200 | 4-inch or 5-inch pipe, muffler optional |
| SCR Simulator, optional but recommended | $200–$500 | Helps prevent NOx sensor-related fault codes |
| EGR Delete Kit, block-off plates / cooler removal | $100–$300 | Often purchased together with the exhaust pipe |
| Professional Installation | $800–$1,500+ | Fewer shops are willing to do this due to legal risks |
Estimated DIY total for 2013–2018 models: about $1,800–$2,500
Estimated DIY total for 2019–2024 models: about $2,200–$3,500
See also : How Much Does It Cost to Delete 6.7 Cummins
Legal and Environmental Risks Specific to DEF Delete
Before modifying the DEF system or the full emissions system, make sure you understand the following risks.
1. High Legal Risk in the United States
Modifying or removing factory emissions systems on road-use vehicles violates U.S. EPA emissions regulations. Vehicle owners may face fines of more than $4,500 per violation. Modified vehicles may fail state inspections and may not be legally registered for road use. Shops that provide delete services may face fines of up to $37,500 per day.
2. Factory Warranty Void
Once emissions-related components are modified, the factory powertrain warranty may be voided immediately. If the engine or transmission fails later, all repair costs may fall on the owner.
3. Lower Resale Value
Most regular buyers do not want to purchase a truck with deleted emissions systems. These vehicles may lose 20%–40% of their resale value.
4. Poor-Quality Parts and Bad Tuning Can Damage the Truck
Low-quality delete kits can cause leaks, sensor damage, and fitment issues. Improper ECU tuning can lead to abnormal power delivery, poor fuel economy, overheating, and in severe cases, permanent engine damage.
5. Environmental Impact
After removing the DEF, DPF, and EGR systems, particulate matter, nitrogen oxides, and other pollutants in the exhaust can increase significantly, contributing to air pollution.
Summary: DEF modification and full emissions delete setups are intended only for off-road, farm, job-site, or race-use vehicles. Do not drive modified vehicles on public roads.
Should You Delete DEF on Your 6.7 Cummins?
In simple terms, it depends on how you use your truck.
If your truck is mainly driven on public roads, including commuting, long-distance driving, or commercial transportation, you should not delete the DEF system or any emissions system. The legal risk, inspection failure, lower resale value, and repair difficulties far outweigh the yearly DEF cost.
If your truck is used strictly for off-road, farm, mining, or race applications and is not driven on public roads, then a full system delete, including DEF, may be considered. In that case, the enforcement risk may be lower, and you may benefit from improved power, reliability, and freedom from DEF-related issues.
However, if you only want to solve DEF crystallization or sensor failures and do not want to remove the DPF or EGR, repairing the DEF system is the correct approach. Cleaning or replacing the injector ($100–$300), replacing NOx sensors ($200–$500), using high-quality DEF, or installing a heater are legal solutions that cost far less than a full system delete.
