Duramax L5P 2017-2021 HP Tuning Emissions Upgrades
Chevrolet and GMC 2017 – 2021 Duramax L5P Tuning
**WE HIGHLY RECOMMEND that you read each field ENTIRELY do not skip over any text as these trucks do not tune as easily as other trucks in the past, they require more parts and following the steps to make YOUR life easier along with OURS!!
**DO NOT remove any hard parts until you have accomplished the full ECM swap and its tuned!
**We also recommend that once you have the ECM/TCM installed and BEFORE you remove any hard parts that you get 3-4 key cycles approximately 30 miles of drive time to see if there are any issues or check engine lights come on.