Best L5P Delete Kit – The Duramax L5P is the latest diesel in GM’s Duramax 6.6L family. That means every imaginable diesel exhaust system is also available. The L5P Delete Kit has a selective cat reduction, diesel exhaust fluid, diesel particulate filter, diesel oxidation cat and gas exhaust system for recirculation.
Although these exhaust systems are great for reducing emissions, they do have some drawbacks. There are not many common problems with the exhaust system on the L5P Delete Kit, but they are expensive to replace if broken. Any DPF system is prone to some kind of clogging and than replacing it can cost over $5k. Moreover, it is also restrictive in terms of performance.
Deleting the L5P DPF system is common for preventive maintenance and performance reasons. Not having all these complex systems will reduce potentially expensive repairs and allow for more energy production. This ultimate guide will discuss the L5P Delete Kit and LP5 Emissions system, the pros and cons of removing the DPF system, and how to delete the L5P DPF system. So let’s start…
What is the Duramax L5P DPF System?
DPF is a diesel particulate filter. When diesel engines burn fuel, they produce “particulate” and exhaust gases. Diesel particulates are small chemical particles that are harmful to the environment and human health when inhaled. A DPF sits inside the exhaust system and captures these particles in the exhaust gas. It then burns them through the regeneration cycle.
As mentioned above, the L5P has an SCR, DOC, DEF and EGR system. The DPF system is actually the last exhaust system in the performance L5P. The first is a diesel oxidation catalyst similar to a conventional catalytic converter. It sits after the pipe in the operating system. SCR system that uses DEF liquid to crack nitrous oxide after DOC. These two systems sit before DPF to burn as much exhaust gas as possible before they enter the particulate filter.
Similar to the LML, the L5P’s SCR and DPF systems are connected to the same pipe in the exhaust. So the operating system is like this: down pipe > DOC > SCR & DPF > cat-back and muffler.
Another exhaust system we mentioned above is EGR or Exhaust Gas Recirculation. This is actually the first exhaust system, but not sitting on the throttle. EGR captures the exhaust gases before they reach the exhaust system and recycles them in the engine, so that the gases are burned again through the combustion process.
What Does an L5P Delete Kit Remove?
Removing the DPF is a little confusing because the L5P DPF disassembly actually removes more than just the DPF system. Moreover, DPF deletion will also delete the DOC, SCR and DPF systems. Since the SCR system is deleted, you also don’t need DEF fluid, which is also deleted technically.
Removing the L5P DPF will delete:
- Diesel Oxidation Catalytic (DOC)
- Selective Cat Reduction (SCR)
- Diesel Exhaust Fluid (DEF, used together with SCR)
- Diesel Particulate Filter (DPF)
So, eventually eliminate the entire exhaust system except EGR, because it is not in the exhaust. The DPF Delete Kit is just one part of the exhaust pipe that is attached to the down pipe and the filter, so it deletes the whole emission system in the exhaust.
Deleting the L5P EGR (L5P Delete Kit)
When people talk about truck deletes, you’ll also hear about DPF and EGR deletes as well. These are completely separate deletions. Interfering with the L5P DPF does not interfere with the EGR system.
Dismantling the EGR system is a bit tricky as it requires blocking the EGR valve and hooking up some hoses. Installing an EGR Delete is more complicated but not much difficult than a DPF because the DPF Delete is literally just part of the gas pipe that is attached.
The EGR system also has an EGR cooler that cools the exhaust air before it is dumped into the intake manifold. The EGR system is not limiting in terms of performance. Therefore, it is removed to prevent the failure of the conventional EGR cooler and is twice as expensive.
Blowing exhaust gases into your intake system and into the combustion chamber sends diesel particles and diesel fuel into the engine. This is generally not good for engine reliability and longevity, so the EGR is usually deleted for preventive maintenance and reliability purposes.
Duramax L5P Delete Kit Pro’s
The two reasons to delete the DPF are reliability and performance. DPFs clog easily and are very expensive to repair. SCR can also fail and require DEF fluid which is annoying and reduces gas mileage. From a performance perspective, all these filters put too much pressure on the operating system, limiting performance and bad for turbo efficiency.
L5P DPF Delete Kit Pro’s:
- Get more than 100whp in turning
- Gas mileage increased by 2-5mpg
- Improved turbo efficiency and reliability
- Reduce the temperature of the flue gas
- Exhaust pressure drop
- No more DEF fluids or regen cycles
- Increase reliability, reduce maintenance costs
One caveat is that the power off of the DPF only matters if you push the L5P too far. The L5P can still easily crank over 800whp with the DPF system fitted, so there’s really no need to remove for performance reasons. If you’re upgrading your turbo, there’s something to do, but if you’re loosening the bolts on the L5P, you don’t have to delete for performance.
Unless you’re chasing extreme power, the only reason to delete the exhaust system is just reliability. It will produce a healthier engine and turbo through lower pressure and lower EGTs, potentially reducing maintenance and repair costs. Plus, you’ll save money on diesel fuel and DEF fluid.
Available Online: LP5 Delete Kit
Duramax L5P Delete Kit Con’s
With great advantages also comes great disadvantages. It’s not about deleting bad systems or making simple decisions. There are many persuasive situations to put your GM truck in tact, such as:
- Decrease in resale value
- Warranty void
- The dealer will not touch your truck
- This is technically illegal and can lead to hefty fines
- It cannot test for errors
- Installation must be DIY (shops don’t do this anymore)
- Harmful to the environment
- Must be used in conjunction with a DPF capable regulator
In case, you don’t worry about the impact on the environment. If so, the biggest reason not to do it is to deal with an illegal vehicle. Dealers and most shops these days won’t touch a deleted truck due to an EPA violation and they certainly won’t install any delete system for you. Warranty goes out the window, if there is one. After registration, the resale value is reduced and it is difficult to check deleted trucks.
In addition to purchasing a delete kit, you will also need to purchase a tuner capable of handling a deleted L5P. They don’t make these off the shelf anymore, so you have to track down a used one or find an adjuster with a ball to fix a delete DPF. In general, shops, tuners, etc. It’s getting harder to find because the EPA imposes heavy fines on these people if they get caught.
Should You Delete Your DPF System?
Added power, improved reliability, and less money spent on fuel seems like a win-win. However, the problem of having an illegal truck can outweigh its benefits. We don’t think we need to do this for output. It really limits performance when you push the envelope, which is not the case with bolt-mods. That means it finally comes down to whether or not you should delete for reliability purposes.
We do not recommend deleting the DPF unless you are one of the few chasers or if the DPF, SCR, DOC have failed. It is just as easy to delete after a failure as it is to delete now. So if your system fails and you can’t afford the $5k repair bill, we recommend doing it as a last solution.
If your exhaust system is good and your power goals are low, keeping your DPF system is probably the best option. Contrary to what you read on various forums, this system is not a L5P killing machine left and right. This engine is very reliable and there are no reports of DPF or EGR significantly affecting reliability or longevity.
How Much Cost to Delete L5P DPF System?
A deletion of Duramax L5P can cost between $1,500 and $4,000. The steps involved in performing the L5P DPF and EGR Delete are described below with costs for each step.
1 – Duramax DPF and EGR Delete kit
Each exhaust component is installed between the downpipe and the cleaner. A DPF Delete kit is basically a pipe that replaces all those components and connects directly to the pipe filter. This part is easy to install as you only need to fasten it. Different tubes range from $300 to $700. However, if you want to upgrade the entire exhaust system, that’s up to you and can cost around $1,000.
On the other hand, the EGR can have around $300. Deleting the EGR is actually bit more difficult than Deleting the DPF and professional consultation is recommended for this purpose.
2 – DPF Tuner Software
This is the most important and most expensive step in the removal process. Tuning the Duramax L5P is not successful without a capable tune, and not every tuner can tune a Duramax motor.
How to Delete Duramax L5P DPF System?
If you’re not interested in what we’ve said above and want to delete your DPF system, here’s how. You will need two things:
1 – L5P DPF Delete Kit
2 – Adapt to the ability of DPF-break
A delete kit is a piece of gas pipe that is attached to the downpipe and muffler. You have several options here, such as replacing only the DPF / DOC unit or choosing a complete lower exhaust system. The second component is the tuner. Most tuners today don’t have built in DPF delete capabilities, so you need a custom tuner or some used one.
1 – L5P Delete Kit
Each exhaust component is located between the downpipe and the cleaner. A simple delete kit is very affordable and only has a single gas pipe that goes from pipe to pipe. This is usually a direct bolt on without modification required, but it can depend on your long bed, short bed, etc. most kit $300 – $400. Alternatively, you can cut off this part of the gas and buy a pipe from some welding shop directly.
The second option is to upgrade the downpipe gas system. There are more options here. You can use a 4″ or 5″ exhaust pipe, hold the filter or remove the cleaner, etc. Ultimately, it determines whether you want a more powerful operating system or not. Depending on what you choose and whether you want stainless steel or aluminum, these options range from $500-$1000+.
If you just want to delete it, get a delete pipe. If you want a complete system, you can choose a more expensive downpipe-back kit. And if you want to go further, you can upgrade the downpipe for less restriction and pressure for $200.
2 – DPF Tuner
Tuners used to tamper with the internal DPF delete tune until they started having problems. One example is H&S, who created the Mini Maxx, one of the best delete tuners. H&S went out of business after heavy fines for selling emissions-altering equipment. Therefore, it is now almost impossible to find a new handheld tuner with this capability.
All these exhaust systems have sensors that are different from each other. If you don’t fix this, you’ll end up with multiple rebuild cycles and a completely unusable truck.
So your choice is either custom tuning or buying a used tuner like H&S Mini Maxx. You can find some tunes available for sale on the internet, you can download something like SCT X4, but again, it’s getting harder and harder to find someone willing to do it.
6.6L Duramax L5P DPF Delete Summary
L5P has four main exhaust systems. EGR, DOC, SCR and DPF. All these systems, except EGR, sit in the operating system. Dismantling the L5P DPF will remove not only the DPF, but also the DOC and SCR components and the need for DEF fluid. The EGR must be deleted separately.
All these exhaust systems are prone to clogging and failure. And it costs thousands of dollars to replace them. Therefore, the disposal of this waste part is popular for the purpose of preventive maintenance, repair and reliability. Additionally, these filters create pressure and restrict exhaust gas flow, which is bad for EGT and turbos.
With the DPF and other components, you will have a healthier and more reliable L5P. Also, while it doesn’t really produce a ton of power, it does create more power potential for those pushing the limits. On the downside, tampering with DPF is illegal and voids warranty, repair, inspection, resale, etc.
The two things needed are a DPF delete kit and an adjuster. Removal kits run from a few hundred dollars to $1k depending on whether you want to replace the entire system or not. A custom setup and track can run you another $1,000. So changing the DPF on an L5P is about $800-$2000 depending on how you do it.
Q1: Can I install an LP5 Delete Kit myself, or should I seek professional assistance?
Installing an LP5 Delete Kit involves complex modifications and requires specific knowledge and tools. It’s generally recommended to seek professional assistance to ensure the installation is done correctly and in compliance with relevant regulations.
Q2: Will removing the emissions components affect my vehicle’s fuel efficiency?
In some cases, removing emissions components may result in improved fuel efficiency. However, the impact can vary depending on various factors, such as driving conditions, tuning, and the overall condition of the vehicle.
Q3: Can I revert back to the original emissions components after installing an LP5 Delete Kit?
Reverting back to the original emissions components after installing an LP5 Delete Kit is possible, but it can be a complex and time-consuming process. It may require sourcing the original parts and reprogramming the vehicle’s engine control unit (ECU) to accommodate the reinstallation. It’s important to consider these factors before making any modifications.
Q4: Will using an LP5 Delete Kit affect my vehicle’s emissions testing or inspection?
Yes, using an LP5 Delete Kit can significantly impact your vehicle’s emissions testing or inspection results. Without the emissions control systems in place, the vehicle is likely to fail the required tests. It’s crucial to check the local regulations and ensure compliance with emissions standards before proceeding with any modifications.
Q5: Are there any alternatives to an LP5 Delete Kit for improving performance?
Yes, there are alternative modifications available for improving performance without completely removing emissions components. Performance tuners and aftermarket exhaust systems designed to enhance power and efficiency while maintaining compliance with emissions regulations are popular options. Consulting with automotive professionals can help you explore these alternatives.
Conclusion (L5P Delete Kit)
In this article, we have discussed LP5 DPF System, Delete, Pro’s & Con’s, legal considerations, warranty implications, and environmental impact. It’s important to approach vehicle modifications responsibly, considering the legal, warranty, and environmental aspects before proceeding. By seeking professional guidance and adhering to applicable regulations, you can make proper choices and enjoy the benefits of automotive modifications while minimizing potential drawbacks.