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2017-2021 GMC/Chevy L5D Duramax 6.6L Tuning | HP Tuners

From: $1,124.99

Gain 145+ HP and increase torque. Maximize efficiency and drastically enhance your truck’s throttle response.

  • Level 1: Stock
  • Level 2: +30 HP
  • Level 3: +65 HP
  • Level 4: +120 HP
  • Level 5: +145 HP

New HPTuners Modified ECMs & TCMs are currently on backorder. We expect to receive them in small quantities and will ship out accordingly.

This tuning package can only be installed using the HP Tuners RTD or MPVI2.

PPEI is making great strides in expanding the performance of on-highway vehicles and only offers emissions compliant tuning.

Modified L5D ECM (Required)

A modified HP Tuners L5D ECM is required to flash your vehicle. Select the option that best fits your need.

HP Tuners RTD

An RTD or MPVI2 is required to tune your vehicle. Upon purchase we will use your RTD to flash your ECM so that it is ready to plug and play. Select this option if you do not already have a device.

Switch on the Fly Tuning (SOTF)

Enable the ability to change tunes through your steering wheel with the OEM Cruise Control buttons.

Flashing Credits (Required)

8 Credits are required to flash your ECM with the RTD (or MPVI2). Please select this option if you do not have credits.

SKU: T-1721DD-HPT Categories: , Tag: Compatible Years: 2017, 2018, 2019, 2020, 2021 Compatible Model/Engine: GMC/Chevy L5D Duramax
Horsepower 350 RWHP

Why choose PPEI for your tuning needs?

We’ve built our team through passion. We are all activists for vehicle improvements and have built our reputation by Redefining the Limits. Each member of our team is expertly trained to perform all tasks based on your needs and our tuning is created by the brightest minds in the industry. Collectively we’ve amassed over 10,000 hours of testing on over 200,000 vehicle in over 30 different countries. We work harder.

What makes PPEI better?

  • Our dedication to the industry.
  • World class engineering team.
  • State of the art dyno facility and testing software.
  • 12 years as industry leaders.
  • Commitment to progress.

How is your tuning processed/delivered?

When you place an order for tuning all of your vehicle data, modifications, and inputs are immediately delivered to one of our elite calibration specialists. Our specialist then manually writes and creates a tune file specifically for your vehicle details. After your tune has passed all of our quality checks, it is delivered via email and stored using our order processing system. This system allows us to keep a detailed record of your vehicle details, tuning adjustments, and provide you with fast and accurate support.

What this means for you:

  • Tuning built to fit your unique vehicle.
  • Quality checked and dyno tested.
  • Fast delivery through our processing system.
  • Smarter support and tuning adjustments.

Is it safe and will it void my warranty?

Our tuning is safer for your vehicle than taking it in for an oil change and you’re always able to return your vehicle to its factory settings to take advantage of warranty services in most scenarios. However, any aftermarket programming has the potential to void the warranty at the dealer’s/manufacturer’s discretion.

Hundreds of thousands of drivers trust PPEI for all of their tuning needs. If you have any concerns or would like to discuss things further, reach out to us today!

Still have questions?

We’re always looking to provide you with all of the information you need to make an educated decision.

Call Us



Modified L5D ECM (Required)

Weight 6 lbs

HP Tuners RTD

Weight 2 lbs

Switch on the Fly Tuning (SOTF)



Flashing Credits (Required)


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