Downpipe & EGR Valve Cooler Delete Kit for 6.6L Duramax L5P Chevy GMC (2017-2023)

$309.26
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Details

he Downpipe & EGR Valve Cooler Delete Kit is the ultimate performance upgrade for your 2017-2023 Chevy Silverado or GMC Sierra equipped with the 6.6L Duramax L5P engine. By eliminating the restrictive factory EGR system and replacing the stock downpipe with a high-flow 3.5-inch stainless steel unit, this kit unlocks noticeable horsepower, torque, and throttle response gains while lowering exhaust gas temperatures. Whether you tow heavy loads or drive your diesel truck daily, this all-in-one delete kit delivers cleaner intake air, faster turbo spool, and reduced long-term maintenance costs. Keep reading to learn how this kit transforms your L5P Duramax.

Brand Model Year Engine Model
Chevrolet Silverado 2500HD / 3500HD 2017-2023 6.6L Duramax L5P
GMC Sierra 2500HD / 3500HD 2017-2023 6.6L Duramax L5P

✅ Exact Fitment Guarantee | If you are unsure about compatibility, please contact us at service@egrperformance.com with your VIN number.

Shipping Details

Ontario CA / Springdale OH / Newark NJ

Package List

Complete Package Contents

  • 1x 3.5 Inch Stainless Steel Downpipe
  • 1x EGR Cooler Delete Block-Off Plate (Billet Aluminum)
  • 1x EGR Valve Delete Plate (Billet Aluminum)
  • 1x High-Temp Silicone Coolant Hose Kit
  • 1x Stainless Steel Dipstick Tube Bracket
  • 1x Set of Gaskets
  • 1x Complete Hardware Kit (Zinc-Coated)
  • 1x Set of Precision Fit O-Rings
Delivery Time

2-5 working days inland in the United States

Attention

Product details

Product Overview

This Downpipe & EGR Valve Cooler Delete Kit removes the factory EGR valve and cooler from your 6.6L Duramax L5P, preventing soot buildup and clogging that robs performance over time.

Instead of hot exhaust gas being recirculated into the intake, fresh, dense, clean air now flows directly into the combustion chamber for more efficient burns.

The included 3.5-inch stainless steel downpipe replaces the restrictive factory unit, allowing exhaust gases to exit the turbine housing faster and reducing backpressure.

Engineered with billet aluminum components, nickel-plated steel flanges, and high-temp silicone hoses, this kit is built to withstand the extreme heat of diesel performance driving.

Designed as a direct bolt-on upgrade for 2017-2023 Chevy Silverado and GMC Sierra 2500HD/3500HD models with the L5P Duramax.

Ideal For

  • Towing and Hauling: Lower EGTs and improved exhaust flow keep your L5P Duramax running cooler under heavy loads, reducing the risk of defueling while towing trailers, boats, or construction equipment.
  • Daily Driving: Quicker turbo spool and improved throttle response make stop-and-go traffic and highway merging feel more responsive and enjoyable.
  • Off-Road Use: Eliminating the EGR system means fewer heat-related failures on steep climbs and dusty trails where clean intake air is critical.
  • Commercial Vehicles: Fleets and work trucks benefit from reduced maintenance intervals and fewer EGR-related breakdowns that cause costly downtime.
  • Engine Performance Upgrades: This kit is an essential foundation for any L5P build, pairing perfectly with tuners, cold air intakes, and larger turbo setups.
  • Long-Term Vehicle Ownership: Removing the EGR system prevents soot and carbon buildup in the intake manifold, extending the life of your engine and reducing repair bills.

Core Advantages

  • Increased Horsepower and Torque: The high-flow 3.5-inch downpipe and EGR removal reduce backpressure and recirculation losses, delivering measurable gains in both horsepower and torque across the RPM range.
  • Improved Fuel Efficiency: With cleaner, denser intake air and more efficient combustion, many L5P owners report a 1-3 MPG improvement in combined driving after installation.
  • Reduced Engine Temperature: By eliminating hot exhaust gas recirculation and improving exhaust flow, this kit lowers exhaust gas temperatures (EGTs) and helps keep coolant temps stable under load.
  • Extended Engine Life: No more soot and carbon buildup clogging the EGR valve, intake manifold, or turbocharger, meaning less wear on critical engine components over time.
  • Direct Bolt-On Installation: Precision-machined flanges and included hardware ensure a factory-like fit without cutting, welding, or modification to your truck.
  • All-In-One Kit: Includes the downpipe, EGR cooler delete plate, EGR valve block-off, high-temp silicone hoses, gaskets, and all necessary hardware — everything you need in one box.

Technical Specifications

  • Material: Stainless Steel (downpipe); Billet Aluminum (EGR delete plates); Nickel-Plated Steel (flanges); High-Temp Silicone (hoses)
  • Finish: Natural Stainless Steel; Zinc-Coated Hardware
  • Downpipe Diameter: 3.5 Inches
  • Condition: 100% Brand New
  • Type: Downpipe & EGR Valve Cooler Delete Kit
  • Warranty: 1 Year Limited Warranty against manufacturing defects

Why Choose EGR Performance

  • Premium Quality Materials: We use only marine-grade stainless steel, billet aluminum, and reinforced high-temp silicone to ensure every kit withstands the harshest diesel environments.
  • Precision Engineering: CNC-machined flanges and CAD-designed brackets guarantee a perfect fit on every 2017-2023 L5P Duramax application.
  • Rigorous Testing: Every kit undergoes pressure testing, heat cycling, and real-world fitment validation before leaving our facility.
  • Dedicated Customer Support: Email us at service@egrperformance.com for fitment verification, installation help, or technical questions.
  • Fast Shipping from USA Warehouse: Most orders ship the same business day from our domestic warehouse, so you get your parts fast.
  • 1 Year Limited Warranty: Every kit is backed by a full 1-year warranty against manufacturing defects.

Troubleshooting and Problem Solving

Common Issues After Installation

  • Check Engine Light: Most commonly caused by EGR-related DTCs that require a custom tune or EGR disable in the ECU calibration.
  • Rough Idle: May indicate an intake leak at the EGR delete plate gaskets or an unmetered air leak.
  • Reduced Power: Often caused by the ECU entering limp mode due to unresolved EGR or exhaust-related fault codes.
  • Coolant/Oil Leaks: Check all silicone hose connections, gaskets, and O-rings for proper seating and torque.
  • Exhaust Leaks at Downpipe: Verify that all V-band clamps and flange bolts are tightened to spec and that gaskets are not damaged.

Error Code Solutions

  • P0401: EGR Flow Insufficient Detected — Install a custom tune that disables the EGR system in the ECU, or verify that the EGR valve delete plate is properly sealed.
  • P0402: EGR Flow Excessive Detected — Ensure the EGR cooler is fully removed and the block-off plate is sealed; a tune is required to fully clear this code.
  • P0420: Catalyst System Efficiency Below Threshold — Common after downpipe installation; requires a catalytic converter efficiency code disable in the tune or installation of a high-flow catalytic converter.

How to Reset Check Engine Light After Installation

  1. Ensure all installation steps are complete and there are no vacuum, coolant, or exhaust leaks.
  2. Connect an OBD-II scan tool to the diagnostic port under the dashboard.
  3. Turn the ignition to the ON position (do not start the engine).
  4. Use the scan tool to read and then clear all stored diagnostic trouble codes.
  5. Start the engine and test drive for 10-15 minutes to allow the ECU to relearn. If the light returns, a custom EGR-delete tune is required.

What to Do If Your Vehicle Loses Power After Installation

  • Check for active DTCs using an OBD-II scanner — limp mode is often triggered by unresolved EGR codes.
  • Inspect all intake and boost piping connections for unmetered air leaks.
  • Verify the downpipe is properly seated and not causing an exhaust restriction or leak.
  • Confirm the coolant system is properly bled and at the correct level — overheating can trigger power reduction.
  • Install or update your custom tune to fully disable EGR and emissions-related monitors.

Long-Term Maintenance Tips

  • Regular Inspection: Every 5,000-10,000 miles, inspect all silicone hoses for cracks, bulging, or oil saturation, and check that all clamps and bolts are tight.
  • Routine Maintenance: Drain and refill the cooling system every 30,000 miles or per the manufacturer's schedule to prevent corrosion in the rerouted coolant lines.
  • Wear Parts Replacement: Replace high-temp silicone hoses every 50,000-75,000 miles, or sooner if signs of degradation appear. Replace gaskets if any are removed during service.
  • Hardware Check: Every oil change interval, verify downpipe flange bolts and V-band clamps are torqued to spec, and inspect the EGR delete plates for any soot or exhaust leaks.
  • Storage Tips: If the vehicle will sit for extended periods, ensure the cooling system is full and the downpipe is free of moisture to prevent internal corrosion.
  • Warranty Reminder: Following these maintenance guidelines will keep your 1 Year Limited Warranty valid.

This Downpipe & EGR Valve Cooler Delete Kit is designed for the 2017-2023 Chevrolet Silverado 2500HD and 3500HD, as well as the 2017-2023 GMC Sierra 2500HD and 3500HD, all equipped with the 6.6L Duramax L5P turbo diesel engine.

The kit requires no permanent modification to your truck's body or frame and installs using factory mounting points. A custom ECU tune is strongly recommended to disable EGR-related fault codes and unlock full performance gains.

Will NOT fit: Cab & Chassis models. This kit is intended for pickup truck body styles only.

For 100% fitment confirmation, please send your VIN number to service@egrperformance.com.

  1. Dispatch Time: Orders will be shipped within 24 hours after successful payment.
  2. Delivery Time: 2-5 business days after dispatch (delivery speed depends on proximity to warehouse location).
  3. Return Window:7 days for unsatisfactory items45 days for quality-related issues
  4. Refund Processing: Refunds will be processed back to your original payment method within 2-4 business days after receiving the automated refund confirmation email (subject to bank verification).

What is a Downpipe & EGR Valve Cooler Delete Kit?

A Downpipe & EGR Valve Cooler Delete Kit is a performance package that removes the factory exhaust gas recirculation (EGR) system and replaces the restrictive stock downpipe on your diesel truck. This reduces backpressure, prevents soot buildup, and improves overall engine efficiency.

How does a Downpipe & EGR Delete Kit work?

The EGR delete plates block off the EGR valve and cooler, stopping hot exhaust gas from being recirculated back into the intake. The larger 3.5-inch downpipe allows exhaust gases to exit the turbo faster, reducing backpressure and improving turbo spool.

What are the benefits of a Downpipe & EGR Delete Kit?

Benefits include increased horsepower and torque, improved fuel economy, lower exhaust gas temperatures, reduced soot buildup in the intake, and a more responsive throttle. It also reduces long-term maintenance costs associated with EGR system failures.

Will a Downpipe & EGR Delete Kit void my warranty?

Modifying emissions equipment can potentially affect your vehicle's factory powertrain warranty. We recommend consulting your dealership or warranty provider before installation. EGR Performance warrants its products against manufacturing defects for 1 year.

Is a Downpipe & EGR Delete Kit legal in my state?

EGR and emissions deletes are intended for off-road and competition use only. They may not be legal for on-road use in states with strict emissions laws, including California. It is your responsibility to verify local regulations before installing this product.

Do I need a tuner for a Downpipe & EGR Delete Kit?

Yes, a custom ECU tune is strongly recommended. Without a tune that disables the EGR system and related emissions monitors, your truck will likely throw check engine lights and enter limp mode. A tuner also maximizes horsepower and torque gains.

How much horsepower does a Downpipe & EGR Delete Kit add?

When paired with a custom tune, most L5P Duramax owners see gains of 30-60+ horsepower and a similar increase in torque. Results vary based on your existing modifications, tune quality, and fuel quality.

How much MPG gain can I expect from a Downpipe & EGR Delete Kit?

Many owners report a 1-3 MPG improvement in combined driving due to more efficient combustion and reduced pumping losses. Actual results depend on driving style, terrain, load, and whether a custom tune is installed.

How long does it take to install a Downpipe & EGR Delete Kit?

Installation typically takes 4-6 hours for an experienced mechanic with the proper tools. First-time DIY installs may take longer. We recommend professional installation to ensure proper fitment and leak-free operation.

Can I install a Downpipe & EGR Delete Kit myself?

Yes, if you have intermediate mechanical skills, a full socket set, torque wrench, jack and jack stands, and penetrating oil. However, professional installation is highly recommended due to the complexity of exhaust and coolant system work.

How often should I maintain my Downpipe & EGR Delete Kit?

Inspect all hoses, clamps, and connections every 5,000-10,000 miles. Replace silicone hoses every 50,000-75,000 miles and service the cooling system every 30,000 miles to keep the kit performing optimally.

Will this Downpipe & EGR Delete Kit fit my 2019 Chevy Silverado 2500HD 6.6L Duramax L5P?

Yes, this kit fits all 2017-2023 Chevy Silverado 2500HD and 3500HD models with the 6.6L Duramax L5P engine, including your 2019 model. It does not fit Cab & Chassis trucks. Confirm with your VIN at service@egrperformance.com.

What is the warranty on this Downpipe & EGR Delete Kit?

This kit comes with a 1 Year Limited Warranty against manufacturing defects. The warranty covers defects in materials and workmanship under normal use. Proper installation and maintenance are required to keep the warranty valid.

Do you offer technical support?

Yes, our dedicated technical support team is available via email at service@egrperformance.com for fitment questions, installation guidance, and troubleshooting. We typically respond within one business day.

How long does shipping take?

Most orders ship the same business day from our USA warehouse. Standard shipping takes 2-5 business days within the contiguous United States. Expedited shipping options are available at checkout.

Can I return this Downpipe & EGR Delete Kit if it doesn't fit?

Yes, we offer a return policy for unused, uninstalled items in their original packaging within the return window. Please contact us at service@egrperformance.com before initiating a return, and always verify fitment with your VIN first.

Installation Difficulty Level

Moderate

Estimated Installation Time

4-6 hours

Required Tools

  • Socket Set (Metric & Standard)
  • Torque Wrench
  • Screwdrivers (Flat & Phillips)
  • Pliers
  • Ratchet & Extensions
  • PB Blaster / Penetrating Oil
  • Drain Pan (for coolant)
  • Jack & Jack Stands

Step-by-Step Installation Overview

  1. Disconnect the battery and drain the coolant. Remove the factory EGR valve, EGR cooler, and stock downpipe from your 6.6L L5P Duramax. Soak all exhaust fasteners with penetrating oil beforehand.
  2. Install the EGR delete plates. Bolt the billet aluminum EGR cooler block-off plate and EGR valve delete plate into place using the supplied gaskets and hardware.
  3. Install the new 3.5-inch downpipe. Position the stainless steel downpipe to the turbo outlet and exhaust system, securing all V-band or flange connections to factory torque specs.
  4. Reroute coolant hoses and reconnect components. Install the high-temp silicone coolant hoses, dipstick tube bracket, and all remaining hardware. Refill the cooling system with the recommended coolant.
  5. Reconnect the battery and perform a test drive. Start the engine, check for leaks, and verify proper operation. A custom tune is recommended to disable EGR-related DTCs and maximize performance gains.

Important Note: No printed installation instructions are included. Professional installation is highly recommended. If you need technical support, please contact us at service@egrperformance.com.