What is an L5P Duramax Delete Kit?
An L5P delete kit is an aftermarket upgrade package designed to remove or bypass restrictive factory emissions hardware on 2017–2020 Duramax engines. These components typically include:
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L5P Delete Pipes / DPF Delete Kit: Replaces restrictive factory exhaust sections with high-flow piping such as the 2017-2025 6.6L GM Duramax L5P 4" Cat & DPF Delete Pipe or a full exhaust upgrade like the 2017-2025 6.6L GM Duramax L5P 5" Downpipe-Back DPF Delete Exhaust System.
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DEF Fluid Delete Duramax Hardware: Bypasses or removes the DEF tank, heater, pump, and injectors to eliminate DEF refill requirements and limp-mode triggers caused by sensor failures.
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L5P Tune and Delete Kit (ECU Custom Tuning): Re-flashes or unlocks the factory engine control unit (ECU) to adjust fuel mapping, disable emissions codes, and unleash additional horsepower and torque.
L5P Duramax Model Year Comparison (2017–2020)
To help you find the exact fitment for your truck, the table below breaks down key specs and compatibility considerations across different model years:
| Model Year | Compatible Trucks | Key Considerations |
| 2017 Duramax Delete Kit |
Chevy Silverado 2500/3500 HD GMC Sierra 2500/3500 HD |
First gen L5P architecture; pairing with a 4-5 Inch DPF Delete Pipe for 2017-2025 L5P Duramax significantly boosts low-end towing torque and fixes initial sensor flaws. |
| 2018 Duramax Delete Kit |
2018 Chevy Duramax 2018 GMC Duramax |
Best delete kit for 2018 Duramax uses T304/T409 stainless steel pipes with custom ECM unlock solutions. |
| 2019 Duramax Delete Kit |
2019 Chevy Duramax 2019 L5P Duramax |
Eliminates frequent DEF refills and improves throttle response on long-haul towing trips. |
| 2020 Duramax Delete Kit |
2020 GMC 2500 / 3500 HD 2020 Chevy Silverado HD |
Requires specific late-model ECM tuning configurations and 4-bolt flange piping to clear fault codes completely. |
Key Benefits of Deleting DEF and DPF on Duramax Engines
1. Enhanced Fuel Efficiency
Factory DPF regen cycles burn extra diesel fuel simply to clean out trapped soot. By running an L5P full delete kit, your engine operates more efficiently, resulting in noticeable MPG gains during highway cruising and heavy towing.
2. Maximum Horsepower & Torque
Stock exhaust systems create significant backpressure. Installing L5P delete pipes such as the 2017-2025 6.6L GM Duramax L5P 4" Downpipe-Back DPF Delete Exhaust System reduces exhaust restriction, enabling your turbocharger to spool up faster and deliver smooth, immediate power across the RPM band.
3. Eliminate DEF System Failures
Deleting DEF on Duramax trucks eliminates common failure points like faulty reductant heaters, DEF fluid quality sensors, and pump malfunctions that can put your 2020 GMC 2500 or Chevy 3500 into limp mode unexpectedly.
What is Included in a Complete L5P Full Delete Kit?
When shopping for the best delete kit for L5P Duramax trucks, ensure your package includes all core hardware and software components listed in the table below:
| Component Name | Main Function | Primary Product Options |
| L5P Delete Pipes (DPF Delete Kit) | Replaces stock DPF and SCR catalytic converters with 4" or 5" straight pipes. |
• 2017-2025 6.6L GM Duramax L5P 5" Downpipe-Back DPF Delete Exhaust System • 2017-2025 6.6L GM Duramax L5P 4" Downpipe-Back DPF Delete Exhaust System |
| EGR & CCV Upgrade Kits | Blocks hot exhaust recirculation and prevents oil sludge accumulation in the intake. |
• 6.6L Duramax L5P EGR Cooler Delete Kit (2017-2025) |
| L5P Tune & ECM Unlock Package | Re-programs the engine control unit to recalibrate fuel injection and clear DTCs. | Prevents Check Engine Lights (CEL) and unleashes up to 100+ extra horsepower. |
How to Choose the Best L5P Delete Kit
When selecting a Duramax diesel exhaust fluid delete kit, consider the following factors:
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Material Quality: Opt for T409 or T304 stainless steel if you live in northern climates with snow and salt road treatment.
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Exhaust Diameter: 4-inch systems are ideal for daily driving and towing, while 5-inch systems offer a deeper, more aggressive exhaust note.
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Engine Longevity Upgrades: Beyond exhaust piping, adding a CCV Reroute Delete Kit for 2017-2025 Duramax L5P 6.6L and an 6.6L Duramax L5P EGR Cooler Delete Kit (2017-2025) prevents oil mist and hot exhaust gases from fouling your intake system.
Conclusion
Upgrading your truck with a Duramax L5P delete package unlocks the true potential of GM’s 6.6L diesel platform. By pairing high-flow L5P delete pipes with specialized EGR/CCV modifications and a custom tuner, you achieve better fuel economy, higher reliability, and superior overall driving performance.
