6.6L GM Duramax L5P Tuning Package | 2017-2026 GMC/Chevy

GM Duramax L5P Tuning Kit (2017-2026) is the tuning-only portion of our complete L5P delete solution — built for owners who already have their EGR delete hardware and exhaust sorted and just need the tuning side handled. This kit gives you everything required to unlock (where applicable), flash, and run custom SOTF or single-calibration tunes on your L5P without piecing together tuning hardware from multiple sources. The L5P All-In-One kit can be found here. Please Note: 2024 to 2026 L5P ECM's must be sent to HP Tuners to be unlocked before it can be tuned (NOT INCLUDED)* What's Included in the L5P Tuning Kit Items Applicable Years 2017-2019 2020-2023 2024-2026 Unlock Tool Upgrade Included Not required Not available OBD2 Flash Delete Tuning Interface Included 4 credits Included 4 credits Included 8 credits 5 Level SOTF Tune Package Included Included Not available Single Calibration Tune Not available Not available Included Everything included is chosen to work together: the tuning interface with the correct number of credits for your year, and the appropriate tuning package for your platform. This kit does not include EGR/cooler delete hardware, CAN BUS plug kit, or exhaust — if you need those, check out our All-In-One Delete Kit or add the delete hardware separately. Important: 2024-2026 L5P models require E42 service, which is not included in this kit. Power gain range: varies by tune and supporting mods Operating range: designed for race use; lower EGTs when properly calibrated Vehicle Compatibility Make Chevrolet GMC Model Silverado 2500HD / 3500HD Sierra 2500HD / 3500HD Year Range 2017-2026 2017-2026 Engine GM 6.6L L5P Duramax Turbo Diesel V8 GM 6.6L L5P Duramax Turbo Diesel V8 Year / ECM Notes 2017-2019: E41 ECM (Unlock Tool compatible) 2020-2023: E41 ECM (Unlock Tool supported with updated process) 2024-2026: E42 ECM — requires E42 service (not included in kit) Select your year set during configuration: 2017-2019, 2020-2023 or 2024-2026 Duramax L5P Tuning Kit Model Year Platform 2026 Duramax L5P Tuning Kit 2026 E42 ECM (E42 service required) 2025 Duramax L5P Tuning Kit 2025 E42 ECM (E42 service required) 2024 Duramax L5P Tuning Kit 2024 E42 ECM (E42 service required) 2023 Duramax L5P Tuning Kit 2023 E41 ECM 2022 Duramax L5P Tuning Kit 2022 E41 ECM 2021 L5P Tuning Kit 2021 E41 ECM 2020 Duramax Tuning Kit 2020 E41 ECM 2019 L5P Tuning Kit 2019 E41 ECM 2018 L5P Tuning Kit 2018 E41 ECM 2017 L5P Tuning Kit 2017 E41 ECM Fitment is year and ECM-specific, which is why you select your exact model range when ordering. 2017-2019 trucks use the E41 ECM and are fully compatible with the Unlock Tool process. 2020-2023 Duramax L5P trucks still run E41 hardware with an updated unlock procedure. 2024-2026 trucks use the newer ECM platform and require external unlock service before tuning. Customization Steps Year Selection: 2017-2019, 2020-2023, or 2024-2026 GM Sierra/Silverado 2500/3500 L5P Duramax. Feature Traditional ECU Swap (E41 ECM) OBD 2 Tuning Interface Complex installation process Yes No Replace ECM required Yes No (for 2017-2023) IMMO / crank relearn required Yes No Core charge No No Improved combustion temps ✅ ✅ Gains with powerful tune flashes ✅ ✅ On-the-fly power level change ✅ 2017-2023 only Included SOTF levels 0 / 50 / 75 / 100 / 150 HP 2017-2023 only Note: 2024-2026 Duramax tunes are single calibration only and require separate E42 service. No SOTF options available. Features Pre-tune requirement: Always flash the calibration before making any hardware changes Unlock Tool Upgrade: 2017-2023: Unlock Tool Upgrade included (No ECM replacement, immobilizer, or crank relearn) 2024-2026: HP Tuners unlock service required (ECM's must be sent to HP Tuners to be unlocked before it can be tuned, service not included with this product) OBD2 Flash Delete Tuning Interface: 4 credits for 2017-2023 8 credits for 2024-2026 5-Level SOTF tuning package (2017-2023 only): 0HP / 50HP / 75HP / 100HP / 150HP Switch On The Fly 2024-2026 variant is a single calibration tune (no SOTF) Benefits Power & torque: Optimized fueling delivers instant gains, especially when paired with supporting exhaust and delete mods Drivability: Smooth shifts and stronger mid-range with custom tunes Simplicity: Unlock Tool Upgrade avoids ECM swaps and relearn steps Flexibility: Pairs with EGR delete hardware and exhaust you already have or are sourcing separately Shipping & Tuning Details Lead times depend on year and configuration. 2024-2026 kits may require additional prep due to E42 service requirements. Review the installation instructions before beginning. Tuning and hardware setup are detailed processes. We appreciate your patience during order preparation. Optional Add-Ons Discover the TCM Tuning Upgrade Kit: Improve shift strategy and drivability. GM Duramax L5P 3.5' Down-Pipe Helps maximize results by removing the DOC after the turbo.