2017 - 2023 L5P Duramax 2500 3500 | Pickup and Cab Chassis | HP Tuners

** Most E41 L5P Duramax no longer require an e41 unlock kit. Customers can now upgrade their E41 ECM directly through the OBDII port—no physical upgrade kit, no controller removal, and no shipping required. 2018–2023 Chevy Silverado / GMC Sierra 2500–3500 (L5P)2019–2023 Chevy Silverado / GMC Sierra 4500–6500 (L5D) Note: 2017 Model years and some 2018 still require the kit. ** GM E90/T93 Upgrade Kit: Designed for 2020-2023 GM vehicles equipped with T93 TCM (transmission control module), this kit enables full tuning capability—without ever removing your controllers from the vehicle. Perform the upgrade quickly and easily from your own garage or shop. This can be used on an unlimited number of TCMs. Credits are still needed to tune the vehicle. 2017-2019 TCMs Can now be unlocked directly through the obd port. NO swap or unlock required. Introducing the HP Tuners for 2017 - 2023 L5P Duramax 2500 3500 | Pickup and Cab Chassis! Get ready to take your truck's performance and reliability to