2001-2007 6.6L GM Duramax LB7 LLY LBZ 5'' Downpipe-Back Exhaust

General Performance & Technical Questions

Q1: What are the primary benefits of an EGR delete on a Duramax?

• Engine Longevity: Stops abrasive soot and carbon from entering your intake manifold and scoring cylinder walls.
• Lower EGTs: Reduces overall engine operating temperatures by eliminating the recirculation of hot exhaust gases.
• Improved MPG: Many owners report up to a 20% increase in fuel economy when paired with a proper off-road tune.
• Turbo Protection: Prevents "carbon choking" of the turbocharger vanes and intake valves, extending the life of your top-end components.

Q2: What tools are required for installation?

• You will need a standard set of metric sockets, wrenches, and screwdrivers. Since the EGR cooler is integrated into the cooling system, you will also need coolant catch pans and fresh Dex-Cool to refill the system after the reroute.

Q3: Will an EGR delete damage my engine?

• No. When installed correctly with supporting tunes, it actually improves reliability. It optimizes airflow, reduces thermal stress on the head gaskets, and prevents the common "clogged EGR" issues that lead to expensive repairs.

Q4: Will removing the EGR cause my truck to smoke?

• With a high-quality "clean" tune (from platforms like EFI Live or EZ Lynk), your truck should not produce excessive black smoke. Without proper tuning, the air-fuel ratio will be unbalanced, leading to poor combustion and heavy smoke.

Q5: Is an EGR delete legal for street use in the U.S.?

• No. These kits are sold strictly for OFF-ROAD / RACING USE ONLY. Under EPA federal law, removing emissions equipment from a vehicle operated on public highways is illegal and will cause the vehicle to fail emissions inspections (Smog Checks).

LLY (2004.5–2005) Specifics

Q6: Does the LLY kit include a high-flow intake pipe?

• Yes. Most LLY kits feature a high-flow intake bridge designed to replace the restrictive factory piece, significantly increasing airflow for your 2005 Duramax.

Q7: Can I install the 2005 LLY kit myself?

• Yes. The LLY is a very DIY-friendly platform. It is a direct bolt-on solution that typically takes 2–3 hours for an experienced enthusiast with basic hand tools.

LMM (2007.5–2010) Specifics

Q8: Which trucks are compatible with the LMM kit?

• This kit is specifically for 2007.5–2010 Silverado and Sierra 2500/3500 HD models equipped with the 6.6L LMM engine.

Q9: How long is the installation for an LMM Duramax?

• Due to the engine bay layout, the LMM is more labor-intensive than the LLY. Expect a 4–6 hour installation time.

LML (2011–2016) Specifics

Q10: What materials are used in the LML delete kit?

• Our LML kits are manufactured from CNC-machined billet aluminum and high-grade stainless steel to ensure they handle the high boost pressures and heat cycles of the 6.7L platform.

Q11: Is this compatible with a 2015 Chevrolet Silverado?

• Yes. It is fully compatible with 2011–2016 LML models, including the 2015 Silverado/Sierra 2500 and 3500 HD.

L5P (2017–2025) Specifics

Q12: What does the L5P EGR delete improve?

• By removing the EGR valve and cooler on the 2017+ L5P, you allow the engine to pull in 100% fresh, oxygen-rich air. This results in more consistent torque and lower coolant temperatures—highly noticeable when towing heavy loads.

Q13: Is the L5P installation complicated?

• While the L5P engine bay is compact, the kit is designed for a precise fit. Most DIYers can complete the installation within a few hours. Note: L5P tuning is specialized; ensure your ECM is unlocked and ready before starting the physical install.

Troubleshooting & Maintenance

Q14: Will this kit fix the issue of intake heater bolts falling into the engine?

• No. This kit deletes the EGR system. The "heater grid bolt" issue is a separate hardware failure. If you are concerned about those bolts, we recommend a "Grid Heater Delete" in addition to this kit.

Q15: Will my truck pass emissions with this kit?

• No. Removing the EGR system is a "fail" for visual and OBDII emissions scans in states that require testing.

Shipping & Delivery Policy

At DieselPerf, we specialize in high-performance diesel emission system accessories. Our mission is simple: to deliver the parts you need with maximum efficiency, security, and transparency. Below are the guidelines we follow to ensure your order reaches you safely.

1. Perfecting Your Delivery

To ensure a seamless experience and avoid unnecessary surcharges, please keep the following in mind:

• Precision Matters: Always verify your shipping address at checkout. Accurate data prevents costly rerouting fees.
• Address Classification: Carriers determine rates based on zoning. If your business is located in a residential area, it will be classified and billed at the Residential Delivery rate.
• Stay Reachable: Please provide a valid phone number. Carriers often need to coordinate delivery windows; missed connections can lead to significant delays.

2. Order Consolidation

To get your parts to you as fast as possible, we ship items as they become available. This means your order may arrive in multiple packages. Rest assured, you will never be charged extra for these split shipments.

3. Our Logistics Network

We partner with world-class carriers, including UPS, FedEx, DHL, USPS, and Amazon Logistics.

• Global Fulfillment: We fulfill orders from our strategic hubs in the U.S. and Hong Kong, prioritizing the location closest to you.
• Lead Times: While most orders arrive within 5–15 business days, specialty items or factory-direct shipments may require additional transit time.

4. Damaged or Missing Shipments

Your satisfaction is our priority. If your order arrives compromised, please follow this protocol:

For Damaged/Incomplete Deliveries:

1. Document Immediately: Note any visible damage or missing pieces on the delivery receipt before signing.
2. Contact Us: Reach out within 2 business days at service@DieselPerf.com or via phone at +1 325-013-1608 / +852 5381 0098.
3. Preserve Evidence: Keep all original packaging and take clear photos of the damage to expedite your claim.

For Lost Shipments:
If a package goes missing, we will initiate a dock check with the carrier (typically taking 2–7 business days). If the items cannot be located, we will work with you to provide a full replacement or a refund.

5. Estimated Timeframes

• Processing: Orders are generally dispatched from our warehouse within 1–2 business days.
• Transit: Standard U.S. ground shipping typically takes 7–10 business days, though many items arrive sooner.
• Holiday & External Factors: Please account for seasonal peaks (Christmas, Thanksgiving, etc.) and unforeseen "Force Majeure" events like extreme weather, which may naturally extend delivery windows.

Customer Support

Our team is here to help you get back on the road.

• Hours: Monday – Friday | 9:00 AM – 6:00 PM
• Email: service@DieselPerf.com

All Dieselperf products enjoy a 1-year limited warranty starting from the date of goods receipt, covering defects in product materials and workmanship.

Warranty Coverage

This warranty only covers failures arising from original material and manufacturing defects under proper installation and normal use. The warranty is non-transferable and exclusively available to the original buyer. An order number or valid purchase receipt is mandatory for warranty claims.

Warranty Exclusions

The 1-year limited warranty does not apply to the following circumstances:

• Normal wear and tear and surface scratches generated during regular use
• Damage caused by improper installation, unauthorized disassembly or modification
• Damage resulting from misuse, accidental impact, negligence and natural disasters
• Natural aging loss of consumable spare parts
• Labor costs incurred from product disassembly, assembly and maintenance

Warranty Claim Process

1. Submit Application: Email customer service with your order number, detailed fault description and clear photos or videos of product defects.
2. Claim Review: Our technical team will verify the issue. Additional information or product return inspection may be required.
3. Settlement Solutions: Upon claim approval, we reserve the right to take one of the following measures:

• Repair the defective product
• Replace with a brand-new authentic item
• Deliver compatible replacement parts for repair

Limitation of Liability

Within the scope permitted by law, Dieselperf shall not be responsible for any special, incidental, indirect or consequential losses, including but not limited to profit losses, business suspension losses and other economic damages.