6.6L Duramax Tuner Harness Plug Kit 2011-2023

Selection Overview for 6.6L Duramax Harness Plug Kits

Choose by engine code first

The collection separates the available kits by the engine designation shown in each title. One listing is for LML 6.6L Duramax applications, and the other is for 6.6L L5P Duramax applications.

Use the listed year range as a boundary

The LML kit title lists 2011-2016 GM, while the L5P kit title lists 2017-2023 Chevy GMC. Do not carry a year range over to the other kit unless the individual product page says so.

Compare vehicle wording before ordering

Pay attention to whether the title says GM or Chevy GMC, because that wording is part of the available fitment evidence. If your truck details are not clearly covered, check the product page before buying.

Fitment and Product Details to Verify

Confirm what the listing actually supports

Before ordering a duramax tuner harness plug, verify the individual product page for the exact engine, vehicle, year range, tuning-related notes, and any included components that are not shown in the collection view.

Do not assume material or installation details

The supplied product titles do not state materials, installation requirements, or warranty terms. Use the product page for those details, and contact EGR Performance through the Contact Us page during published Monday-Friday business hours if you need help reviewing a listing.

Check legal use before purchase

Because these are tuner-related harness plug kits, they are intended only for off-road use. Buyers should check applicable local regulations before purchasing.

Products in This Collection

• Tuner Harness Plug Kit for 6.6L L5P Duramax Chevy GMC (2017-2023) Replace for Shibby Engineering: L5P 6.6L Duramax option with Chevy GMC and 2017-2023 fitment wording in the title.
• Tuner Harness Plug Kit for LML 6.6L Duramax SHIBBY ENGINEERING 2011-2016 GM: LML 6.6L Duramax option with GM and 2011-2016 fitment wording in the title.

Frequently Asked Questions About Duramax Tuner Harness Plug Kits

Which trucks are represented in this collection?

This collection includes one tuner harness plug kit title for LML 6.6L Duramax GM applications from 2011-2016 and one title for 6.6L L5P Duramax Chevy GMC applications from 2017-2023. Use those year ranges as product-level boundaries, then open the individual listing to confirm the full fitment notes before ordering.

How do I choose between the LML and L5P listings?

Start with the engine code shown for your truck. The LML listing and the L5P listing are separate, so do not select by displacement alone. Match the year range, engine designation, and vehicle wording in the product title, then review the product page for any additional application notes.

What is a duramax tuner harness plug kit used for?

The supplied product titles identify these as tuner-related harness plug kits for specific 6.6L Duramax applications. The titles do not state performance results, included electronics, connector style, or installation requirements. Treat the collection as a fitment-based shopping category and check the individual product page for the exact kit details.

Can I assume a 2017-2023 kit also fits an earlier LML truck?

No. The 2017-2023 listing is tied to 6.6L L5P Duramax Chevy GMC wording, while the 2011-2016 listing is tied to LML 6.6L Duramax GM wording. Do not carry one year range or engine code over to the other product unless the individual product page clearly supports it.

What details should I verify before adding a kit to the cart?

Check the engine code, listed year range, vehicle wording, and any connector or configuration notes shown on the product page. If your truck information does not match the listing cleanly, use the Contact Us page during published Monday-Friday business hours for help reviewing the available product information.

Do these listings include material or installation information?

The supplied product titles do not state materials, tools, installation steps, or setup time. Because those details are not shown at the collection level, use the individual product page for the most specific information available. Do not assume included components or installation requirements from the collection title alone.

Are these tuner harness plug kits for street use?

Because these are tuner-related harness plug kits, they are intended only for off-road use. Buyers should check applicable local regulations before purchasing. The collection information does not establish emissions compliance, tuning requirements, or vehicle inspection status, so confirm legal use for your application before ordering.

Do I need tuning or programming with these products?

The product titles show tuner harness plug kits, but they do not provide programming instructions or identify a required tuning device. Review the individual product page for any setup notes that are actually listed. If the page does not state a programming requirement, do not assume one from the collection name.

What is the return, warranty, and support policy?

Unused products may be returned within 45 days of delivery when the Return & Exchange Policy conditions are met. Return shipping responsibility depends on the reason for the return. Review the current policy and use the Contact Us page for assistance. Check the individual product page for any applicable warranty terms.