2024-2025 Duramax L5P DieselR RTD4 Custom Tuning - Unlocked ECM Required
2024-2025 Duramax L5P DieselR RTD4 Custom Tuning - Unlocked ECM Required is backordered and will ship as soon as it is back in stock.
Confirm vehicle fitment
Confirm vehicle fitment
Confirm fitment before ordering. Match the year, make, model, trim, engine, drivetrain and selected options shown on this page. If any detail is unclear, search your exact vehicle or contact us before checkout.
Shipping expectations
Shipping expectations
Availability and processing time can vary by manufacturer. Available shipping choices and charges appear at checkout. Tracking is emailed after shipment. Oversized, special-order and supplier-shipped items can require additional processing time.
Returns and cancellations
Returns and cancellations
Please review eligibility before purchase. Installed, used, electronic, custom, special-order and clearance items may have return restrictions. Contact us promptly if you need to change or cancel an order.
What’s included
What’s included
The product description and selected variant determine what is included. Items shown in lifestyle or installation photos are not included unless they are specifically listed in the description.
2024-2025 Duramax L5P DieselR RTD4 Custom Tuning - Unlocked ECM Required is backordered and will ship as soon as it is back in stock.
Buy with confidence
Verify fitment, selected options, availability and included components before checkout. Secure payment options and order confirmation are provided at checkout.
Description
Description
2024-2025 Duramax L5P DieselR RTD4 Custom Tuning - Unlocked ECM Required
The 2024–2025 L5P MPVI3 Tune File that customers have been waiting for is now available. This is a single-level, +125HP custom tuning file created for the 2024-2025 6.6L Duramax L5P equipped with the latest E42 (Global B) ECM. It’s written for the HP Tuners MPVI3 platform and designed to deliver clean power with no guesswork.
This MPVI3 custom file is dyno-tested on real 2024–2025 L5P trucks. The stock output baseline was 433HP. With this file, our dyno pulled 575HP and 1,230 lb-ft of torque. Speed limiter has been removed.. It’s calibrated for drivability, towing, and power under load — not just theoretical numbers. It’s a safe, no-nonsense first step into real E42 tuning.
To run this file, your ECM must be unlocked using the Dieselr E42 Upgrade Service. We require your VIN before purchase, and you’ll complete a tuning form after unlock.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
Product features
Use this section to highlight specific product features to your customers.
Product comparison grid
Add content here to explain a bit about the range of products on offer and which ones may be most suitable for your customers.




