These days, diesel and overland truck owners are looking to improve performance to boost fuel efficiency, promote vehicle or engine longevity, and increase productivity. A stronger, faster tow-rig is always preferred, so it’s no surprise that some diesel owners have taken to carrying out a diesel delete (DPF). What is a DPF delete, and is it safe to do for your vehicle?Â
Table of Contents
- What is a Diesel Particulate Filter and How Does It Work?
- What is a DPF Delete?
- Why Would Diesel Owners Delete Emissions Equipment?
- DPF Delete Performance Gains Are Minimal
- Proper Maintenance Can Reduce Emissions Equipment Concerns
- Make the Right Choice
What is a Diesel Particulate Filter and How Does It Work?
In 2008, the Environmental Protection Agency’s Diesel Emissions Reduction Act began requiring truck manufacturers to follow more stringent emissions standards. Some major additions that companies had to include were an exhaust gas recirculation system (EGR), a diesel particulate filter (DPF, which you can learn about in the video above by Lubrizol360) and a diesel nitrogen oxide filter. Selective catalytic reduction systems (SCR) are also required.
Here’s what they do:
- EGR: Helps reduce temperatures and emissions by rerouting exhaust into the combustion chamber
- DEF: Helps eliminate soot in the engine, which gets stored in an exhaust system canister.
- DPF: Ensures soot, ash and other particles are trapped and not released
- Oxide filter: Blocks or reduces tailpipe fumes to lower emissions
- SCR: A filtration system that uses diesel exhaust fluid (DEF) and chemical reactions to convert harmful nitrogen oxide emissions into harmless nitrogen gas and water vapors
A diesel particulate filter forces exhaust gases to flow through the channel walls, which allows the particulates or harmful elements to be physically captured. Chemical reactions then occur — carbon monoxide and hydrocarbons are converted into carbon dioxide and water.
During filtration, up to 90% reductions are possible for particulate matter, carbon monoxide and hydrocarbons. This significantly reduces the harmful emissions produced by the diesel exhaust system. Without the DPF, those emissions would damage the environment.
What is a DPF Delete?
As Dark Iron Diesel discusses in the video above, a DPF delete refers to physically removing the diesel particulate filter from the truck. Alternatively, a more general diesel delete involves removing any or all emissions equipment.
After the DPF is removed, the vehicle’s engine control unit (ECU) needs to be reprogrammed using special kits or tools. The truck’s computer can detect when the DPF has been removed, which will then cause myriad operational issues, including putting the engine in limp mode.
However, some DPF delete kits allow users to bypass these restrictions while avoiding the physical deletion of critical functions. There are also aftermarket diesel engine fluid (DEF) and EGR delete kits people can use. Either way, the process is about removing or disabling these systems for the performance gains they may provide.
Why Would Diesel Owners Delete Emissions Equipment?
Emissions technology and equipment have come a long way. They are now more reliable than ever. However, DPFs have a less than phenomenal reputation in the diesel ownership world. EGR, DPF and SCR systems provide extra failure points for vehicles and can cause performance issues. For example, EGR valves can stick and SCR components can malfunction. This becomes a bigger concern when proper maintenance routines are not followed.
As most diesel truck owners rely on their vehicles for daily operations and to make a living, downtime can be a huge concern.
Moreover, removing emissions equipment from older vehicles could offer a significant fuel efficiency bump. However, many of the trucks this applies to were made before 2010. Modern models are less affected by this rule. Several improvements, like the addition of SCR technologies, rendered this point moot. Some modern diesel vehicles have even seen improved fuel economy due to this tech.
Finally, the diesel community has a strong misconception that emissions technologies slowly kill engines. Filters might become clogged, valves and sensors might break down, and other incidents might wear down the working engine faster than normal. While it is true that they can effectively alter performance when malfunctioning, it’s much less likely modern engines will fail. However, those performance concerns are a hot issue nonetheless.
You can implement diesel modifications that are not illegal or harmful if you are looking for performance gains, such as installing a secondary fuel filter, conducting regular intake cleanings or getting a custom dyno tune.
The reason the EPA requires emissions equipment in the first place is because these harmful chemicals and gases increase cancer risks. Removing them could also make you responsible for exposing others to these dangerous emissions, in addition to harming the planet.
DPF Delete Performance Gains Are Minimal
True diesel enthusiasts who have tested the before and after of a DPF delete report that the gains are minimal. However, it’s illegal and may lead to fines, insurance concerns or a nonroadworthy vehicle. Therefore, it’s not worth doing for such small gains in performance.
Installing a second filter might be a better option because it can help reduce fuel contamination while the engine is running, improving efficiency. Another option includes upgrading to an aftermarket DPF back exhaust, which will provide performance and power gains.
Proper Maintenance Can Reduce Emissions Equipment Concerns
Photo by Christopher John on Unsplash (license)
While they’re not perfect, emissions systems can be kept optimal through regular maintenance and performance monitoring. Consistently cleaning out the DPF and other systems or taking the vehicle in for regular systems checks can ensure everything is in shape.
Proper maintenance standards are also important. Using the appropriate oil for a truck with an EGR-ready engine helps reduce soot and ash contamination.
Make the Right Choice
Should you perform a DPF delete on your diesel truck or overland vehicle? Probably not. If you want a roadworthy machine that’s legal to drive, it’s not worth the many risks involved. It’s recommended practice to help reduce total emissions, especially because of the harm these chemicals and gases can cause.
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Hero Photo by Brad Sauter via Shutterstock
Jack Shaw is an accomplished automotive writer with a flair for adventure and a passion for all things off-road. Having written for notable sites such as Modded, Ford Muscle, Offroad Xtreme, and more, his articles are a testament to his knowledge and love for the automotive industry.