Does it fit Cab & Chassis trucks?

No, it does not fit Cab & Chassis trucks.

What model years does this kit fit?

It fits late 2015.5–2016 models.

What connection style is required?

It is designed for trucks with a 3-bolt flange connection to the turbo-direct pipe.

Will it fit early 2011–2015 models?

No, it will not fit early 2011–2015 models with a V-band style clamp connection.

Yes, a DPF-delete capable tuner is required.

2015.5-2016 6.6L GM Duramax LML 4"& 5"DPF Delete Race Pipe DieselPerf

2019-2025 6.7L Dodge Ram Cummins 5'' Downpipe-Back DPF Delete Pipe DieselPerf

2001-2007 6.6L GM Duramax LLY LBZ LB7 4" & 5"Downpipe-back Exhaust DieselPerf

2015.5-2016 6.6L GM Duramax LML DPF Delete Race Pipe 4" & 5"

$235.00

~~$279.00~~ Sale $235.00

PATRIOT DAY SALE: 13% OFF

In stock

Ships from USA in 1-2 Business Days

Style

4"Cat&DPF Delete Pipe(2015.5-2016) 4" Downpipe-Back(2015.5-2016) 5" Downpipe-Back(2015.5-2016)

Shipping Policy at Dieselperf, Learn More

Product Specifications

SKU DIPSJ-025
Vehicle Fitment 2015.5-2016 LML 6.6L Duramax

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Please note: All sales of exhaust pipes, straight pipes, and engine pipes are final and Non-Returnable and Non-Refundable

Upgrade your 2015.5–2016 Chevrolet Silverado or GMC Sierra 2500HD/3500HD equipped with the 6.6L Duramax LML engine with a 4-inch or 5-inch exhaust configuration designed for the later 3-bolt flange connection.

Available options include a shorter 4-inch CAT & DPF delete pipe, a complete 4-inch downpipe-back exhaust system, and a complete 5-inch downpipe-back exhaust system. Each configuration is manufactured from T409 stainless steel with mandrel-bent tubing.

These products do not fit earlier 2011–2015 trucks with a V-band connection or Cab & Chassis models. Some shorter cab, bed, or wheelbase configurations may require pipe trimming during installation.

Check your inlet connection before you order this DPF delete race pipe

Key Features

Three Exhaust Configurations:
Choose a shorter 4-inch CAT & DPF replacement pipe or a complete 4-inch or 5-inch downpipe-back exhaust system.

2015.5–2016 LML Fitment:
Designed for compatible late-production LML Duramax pickups equipped with the later 3-bolt exhaust flange.

4-Inch and 5-Inch Pipe Options:
The 4-inch configurations provide a more moderate exhaust setup, while the 5-inch downpipe-back system offers a larger exhaust path and deeper tone.

T409 Stainless Steel Construction:
Built for durability under high exhaust temperatures and exposure to demanding road conditions.

Mandrel-Bent Tubing:
Smooth bends help maintain a consistent internal pipe diameter through curved exhaust sections.

Heavy-Duty Pipe Walls:
Approximately 2 mm wall thickness provides added structural strength for diesel truck applications.

Designed for Freer Exhaust Flow:
The larger tubing and replacement sections are designed to reduce exhaust restriction and help the engine breathe easier. Actual results vary by vehicle condition, configuration, and other modifications.

Available Options

Option	Product Type	Pipe Size
4" CAT & DPF Delete Pipe	Short replacement section	4 inch
4" Downpipe-Back	Complete downpipe-back system	4 inch
5" Downpipe-Back	Complete downpipe-back system	5 inch

4" CAT & DPF Delete Pipe

This shorter replacement section is designed to replace the factory CAT and DPF exhaust section while retaining compatible portions of the existing exhaust system. It is not a complete downpipe-back exhaust.

4" Downpipe-Back

This complete exhaust system connects downstream of the factory turbo downpipe and replaces the exhaust toward the rear of the truck. The 4-inch diameter provides a more moderate exhaust tone and pipe size.

5" Downpipe-Back

This complete downpipe-back system uses larger 5-inch tubing for a deeper and more aggressive diesel exhaust tone.

A muffler and exhaust tip are not listed as included with any of the available options.

Technical Specifications

Specification	Detail
Product Types	CAT & DPF replacement pipe or downpipe-back exhaust system
Model Years	2015.5–2016
Vehicle Models	Chevrolet Silverado and GMC Sierra 2500HD/3500HD
Engine	6.6L Duramax V8
Engine Code	LML
Pipe Diameter	4 inch or 5 inch
Material	T409 stainless steel
Wall Thickness	Approximately 2 mm
Construction	Mandrel-bent tubing
Front Connection	3-bolt flange
Cab & Chassis Fitment	Not compatible

Vehicle Fitment

Chevrolet Silverado

Late 2015 Silverado 2500HD with 6.6L Duramax LML
Late 2015 Silverado 3500HD with 6.6L Duramax LML
2016 Silverado 2500HD with 6.6L Duramax LML
2016 Silverado 3500HD with 6.6L Duramax LML

GMC Sierra

Late 2015 Sierra 2500HD with 6.6L Duramax LML
Late 2015 Sierra 3500HD with 6.6L Duramax LML
2016 Sierra 2500HD with 6.6L Duramax LML
2016 Sierra 3500HD with 6.6L Duramax LML

Important Fitment Notes

The truck must have the later 3-bolt exhaust flange.
Does not fit earlier 2011–2015 trucks equipped with a V-band connection.
Does not fit Cab & Chassis models.

What’s Included

Depending on the selected option, the package includes:

Selected 4-inch CAT & DPF replacement pipe sections; or
Selected 4-inch downpipe-back exhaust pipe sections; or
Selected 5-inch downpipe-back exhaust pipe sections
Exhaust clamps
Exhaust hangers

The number and shape of individual pipe sections vary by selected configuration.

A muffler, exhaust tip, sensors, electronic components, flange gasket, bolts, and other unlisted components are not confirmed as included.

Installation Notes

Confirm that your truck uses the later 3-bolt exhaust flange before removing the factory exhaust. These products are not compatible with earlier trucks equipped with a V-band-style connection.

The CAT & DPF replacement pipe and the complete downpipe-back systems replace different portions of the exhaust. Confirm the selected configuration before installation.

Minor cutting or trimming may be required for certain short-wheelbase, cab, or bed combinations. Test-fit and align all pipe sections before cutting or fully tightening the clamps.

The available product information does not confirm whether welding is required or which factory gaskets, bolts, clamps, or mounting components must be reused.

Installation time varies depending on the selected configuration, vehicle condition, corrosion, wheelbase, available tools, and installer experience. Professional installation is recommended.

After installation, inspect clearance around the frame, suspension, spare tire, fuel lines, brake lines, wiring, and body. Recheck and retighten all exhaust connections after the first complete heat cycle.

Frequently Asked Questions

What is the difference between the CAT & DPF Delete Pipe and the downpipe-back systems?
The 4-inch CAT & DPF Delete Pipe is a shorter replacement section. The 4-inch and 5-inch downpipe-back options replace a larger portion of the exhaust from downstream of the factory turbo downpipe toward the rear of the truck.

Do the downpipe-back systems replace the factory turbo downpipe?
No. They connect downstream of the factory turbo downpipe. They are not turbo-back exhaust systems.

How do I know whether this fits my 2015 truck?
Inspect the front exhaust connection. These products require the later 3-bolt flange and do not fit earlier trucks equipped with a V-band connection.

What is the difference between the 4-inch and 5-inch downpipe-back systems?
The main difference is pipe diameter. The 5-inch system provides a larger exhaust path and generally produces a deeper tone. The 4-inch system offers a more moderate configuration.

Do any of the available options include a muffler?
A muffler is not listed as included with any of the available configurations.

Does the package include an exhaust tip?
An exhaust tip is not listed as included.

Will cutting be required?
Some shorter cab, bed, or wheelbase configurations may require trimming an intermediate pipe. Test-fit the selected system before cutting.

Is welding required?
The available product information does not confirm whether welding is required. Review the physical connections before beginning installation.

Are clamps and hangers included?
Yes. Exhaust clamps and hangers are listed as included. Exact quantities may vary by selected configuration.

Does this product fit Cab & Chassis trucks?
No. These products are not compatible with Cab & Chassis applications.

Will additional vehicle calibration be required?
Replacing factory emissions-related exhaust components may affect vehicle operation and diagnostics. Consult a qualified professional to confirm vehicle compatibility, installation requirements, and applicable legal restrictions.

Compliance Notice

These products alter or replace factory emissions-related exhaust components. The purchaser and installer are responsible for confirming compliance with all applicable federal, state, and local laws before purchase, installation, or use.

System Specifications & Material

Q1: What’s the difference between 4-inch and 5-inch exhaust systems for diesel trucks?

4-inch Systems: Ideal for stock to moderately tuned engines. This diameter maintains the necessary backpressure to optimize low-end torque, making it the perfect choice for daily driving and consistent towing.
5-inch Systems: Designed for high-horsepower performance builds. These systems maximize exhaust flow to aggressively lower Exhaust Gas Temperatures (EGTs) and unlock peak power for racing or extreme heavy-duty applications.

Q2: Can a magnet stick to this exhaust pipe? Is it genuine stainless steel?

Yes. This pipe is crafted from T-409 Stainless Steel. Unlike 304-grade (non-magnetic), T-409 is a magnetic alloy specifically engineered for automotive exhaust environments. It offers a superior balance of corrosion resistance, high-temperature durability, and cost-effectiveness compared to aluminized steel.

Q3: How thick is the exhaust pipe, and what’s its service life?

The pipe features a heavy-duty 14-gauge (approx. 2mm) wall thickness. Built from durable T-409 stainless, it is engineered to withstand extreme exhaust heat and off-road vibrations for years of rust-resistant, reliable use.

Fitment & Compatibility (LML Duramax)

Q4: Is this a full Turbo-Back system or a Downpipe-Back system?

This is a Downpipe-Back system. It replaces all exhaust components starting after the factory downpipe, including the restrictive DPF and stock piping. To achieve a true "Turbo-Back" setup, an aftermarket performance downpipe is required in addition to this kit.

Q5: I have a 2015 Duramax—how do I ensure I choose the right kit?

The 2015 model year was a "split" year for the LML Duramax. You must verify your truck’s downpipe connection type:Early 2011–2015 Models: The exhaust downpipe attaches via a V-band clamp.Late 2015.5–2016 Models: The exhaust downpipe uses a 3-bolt flange connection.
Please confirm your specific connection design to ensure a perfect bolt-on fit.

Q6: Is this pipe compatible with my LML if I upgrade to a 5-inch exhaust?

Absolutely. This component is engineered to be fully compatible with both 4-inch and 5-inch performance exhaust configurations. It is a top-tier choice for 2015–2016 LML owners looking to maximize exhaust scavenging and overall engine performance.

Performance & Legal Compliance

Q7: Will a DPF delete kit boost my truck’s performance?

Yes. By removing the factory restrictions, you will experience:Lower EGTs: Essential for protecting engine components under load.Faster Spool: Improved turbocharger and throttle response.Better MPG: Increased fuel efficiency (when paired with proper ECU tuning).Reliability: Permanent elimination of DPF clogging and costly "Regen" cycle failures.

Q8: Can I legally drive my truck with a DPF delete on public roads in the US?

Off-Road / Racing Use Only. Removing the Diesel Particulate Filter (DPF) is a violation of U.S. EPA and CARB emissions regulations. Use on public highways may result in significant fines, failed emissions inspections, and legal penalties. Always verify your local and state laws before installation.

Q9: Do I need a tuner after installing this exhaust?

Yes. Modifying the DPF system on a Duramax LML requires a "DPF-off" tune (e.g., EFI Live or EZ Lynk). Without a proper tune, the truck will trigger a Check Engine Light (CEL) and enter "Limp Mode."

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:

Document Immediately: Note any visible damage or missing pieces on the delivery receipt before signing.
Contact Us: Reach out within 2 business days at service@DieselPerf.com or via phone at +1 325-013-1608 / +852 5381 0098.
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

Submit Application: Email customer service with your order number, detailed fault description and clear photos or videos of product defects.
Claim Review: Our technical team will verify the issue. Additional information or product return inspection may be required.
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.