Diesel Delete Kits 101

To start off, let’s discuss the three most common diesel delete kits available today:

DEF Delete Kit: This is a process where you remove your diesel truck’s entire DEF system and SCR (Selective Catalytic Reduction) technology so that it no longer requires you to have diesel exhaust fluid to operate. Diesel exhaust fluid is formed by combining urea and deionized water. When combined with exhaust gases, it breaks down the ammonia and carbon dioxide for cleaner exhaust. Learn more here.

Benefits of a DEF delete: You save money on buying fluid and have increased exhaust notes, but removing the DEF system does not add significant fuel efficiency. The jury is still out on whether or not it can increase the longevity of your engine.

Is a DEF delete legal?

DEF systems are required on all vehicles that have them factory-installed, according to the EPA.

DPF Delete Kit: This is an aftermarket diesel accessory used to remove your truck’s diesel particulate filter (DPF), which captures small soot particles, preventing them from being let out into the atmosphere.

Benefits of a DPF delete: This is one of the best-known ways to quickly increase horsepower and fuel economy on diesel trucks.

Is a DPF delete kit legal?

Deleting your DPF is only legal for race and competition use. If your diesel is only registered for street use, you cannot delete your DPF unless you’re willing to risk not passing emissions tests.

EGR Delete Kit: This is another aftermarket diesel part assembly that involves removing your truck’s exhaust gas recirculation (EGR) system. Your EGR system is what reduces the exhaust emissions and is a part that is required in order to abide by emissions laws nationwide.

Benefits of an EGR delete: The removal of your EGR system allows the engine to be run at cooler temperatures and have better fuel economy.

Is an EGR Delete Kit legal?

An EGR delete kit is illegal in all 50 states.

Is my warranty void if I perform a muffler delete or use a diesel delete kit?

In short, yes and no. Should a problem arise on your vehicle which is still under warranty, the dealer will need to prove that the removal of your DEF, DPF or EGR system or the adding of aftermarket performance tuning this 100% caused the item under warranty item to be adversely affected.

The following are a few scenarios where your warranty would and would not be covered after using a diesel delete kit:

Under Warranty

Your Ford F-250 with a 6.7L Powerstroke has aftermarket performance tuning and a diesel delete kit. Let’s say your water pump goes out and you’re still under warranty and you take it back to the dealer; more than likely they will replace the pump because it would be very hard to prove that your aftermarket products caused this issue. Furthermore, they do have the right to refuse to service your vehicle because it is illegal to drive on highway roads, thus prohibiting them from performing an emissions test on your vehicle after service.

Service, But No Warranty

Now, let’s say you have a diesel delete kit and aftermarket performance tuning installed on your Chevy Silverado 2500 with a 6.6L Duramax, and your CP4 injection pump goes out. More than likely, the dealer is not going to cover this repair under warranty because it is very obvious that the aftermarket tuning was designed to alter the vehicle’s performance beyond the limits it was designed for, and you will be paying for this one out of pocket!

No Service, No Warranty

An example of a service which might not be covered under warranty would be if your Transmission goes out in your Dodge Ram 2500 with a 6.7L Cummins Diesel, the dealer would more than likely be able to prove that the aftermarket tuning created more horsepower, altered shift strategy & shift firmness and that the tuning which was applied to your vehicle was altered to a point which was above what it was rated for then more than likely they would deny this service for you and this would become an out of pocket expense.

At the end of the day, it really just depends what exactly your specific dealership’s policy is on diesel delete kits.

The Repercussions Of Diesel Delete Kits

  • The EPA could issue a heavy fine if your truck fails an emissions test due to a deleted exhaust component.
  • If you bring your truck to a dealership to have it serviced, the dealership could potentially refuse to work on it if they find exhaust components have been removed.
  • Your truck’s trade-in value immediately drops once you remove diesel exhaust regulation components because dealerships will have to pony up $3-4k to have new ones installed.


Have any questions about diesel delete kits?

Feel free to call our diesel shop at Texas Diesel Company or contact us with any questions or concerns you may have. We’re more than happy to help!