It’s more responsive in the pedal.
6.6L Duramax L5P Downpipe-Back Exhaust System | 2017–2026
2017 - 2019
4-inch Downpipe-Back
No Muffler
Regular price
$515.00
Regular price
$825.00
Sale price
$515.00
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GM Duramax L5P (2017 - 2026)
6.6L Duramax L5P Downpipe-Back Exhaust System | 2017–2026
6.6L Duramax L5P Downpipe-Back Exhaust System | 2017–2026
SKU: SKU:ESSS-GM-17-4
Regular price
$515.00
Regular price
$825.00
Sale price
$515.00
Quantity
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Introduction
Unlock the full potential of your Chevrolet Silverado or GMC Sierra 2500HD/3500HD 6.6L Duramax L5P with this Downpipe-Back Race Exhaust System. It's built from 16-gauge stainless steel and available for both 2017–2019 and 2020–2026 trucks. Choose a 4-inch or 5-inch system, then choose to run it with or without a muffler. Every version delivers unrestricted flow, sharper throttle response and a deep, aggressive tone built for serious off-road and competition use.
Note: This system is for off-road and race applications only and must be paired with off-road race tuning.
Choose Your Configuration
Build the system that fits your truck and your goals by picking one option from each of the three choices below.
1. Model Year
- 2017–2019 GM 2500HD/3500HD Duramax L5P
- 2020–2026 GM 2500HD/3500HD Duramax L5P (with OEM-style 4-bolt turbo flange)
Each version is bent to fit its model generation precisely, so be sure to select the year range that matches your truck.
2. Pipe Diameter
4-Inch Downpipe-Back
A strong all-round choice for trucks that tow and daily drive. It improves flow and spool over stock while keeping the tone slightly more restrained than the 5-inch system.
5-Inch Downpipe-Back
Maximum airflow for built trucks and competition use. The larger diameter offers the least restriction and the deepest, most aggressive exhaust note.
3. Muffler Option
No Muffler
A straight-through pipe with nothing in the path. This is the loudest and least restrictive setup, ideal for dedicated race and pull trucks.
With Muffler
Adds a stainless steel muffler to the system for a more controlled tone. A good fit if you want the flow of a race exhaust with less noise on long drives.
Features
- 16-gauge stainless steel construction for strength and corrosion resistance
- 4-inch and 5-inch diameter options to tailor flow, tone and application
- Optional stainless steel muffler for a more controlled exhaust note
- Downpipe-back race design for maximum airflow and power
- OEM-style hangers and prewelded contour bends for accurate fitment
- Improved flanges and stainless clamps for secure, leak-free connections
- OEM-style 4-bolt turbo flange (2020–2026 version only)
- Bung-free design for a clean, unrestricted exhaust path
- All necessary hardware included for easier installation
Benefits
- Increases horsepower and torque by reducing exhaust restriction
- Helps lower EGTs when towing and under heavy load
- Improves turbo spool and throttle response
- Enhances airflow for better engine breathing and efficiency
- Produces a deep, performance-driven exhaust tone, with or without the muffler
- Premium stainless steel for long-term durability in harsh conditions
Compatibility
Years: 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025, 2026
Make: GMC, Chevrolet
Model: GMC Sierra 2500HD / 3500HD, Chevy Silverado 2500HD / 3500HD
Engine: 6.6L Duramax V8 Turbo Diesel (L5P)
Configurations: EC, CC, SB, LB and Dually
Please Note: Not compatible with Cab & Chassis models.
Technical Specifications
- Material: 16-gauge stainless steel
- Diameter: 4-inch or 5-inch mandrel-bent tubing
- Muffler: Optional (No Muffler or With Muffler)
- Configuration: Downpipe-back, single side exit
- Finish: Natural brushed stainless
- Hardware: Stainless clamps, contour-bent hangers, prewelded flanges
- Design: Bung-free, high-flow race system
Installation & Notes
- Direct bolt-on installation using factory hanger points
- No cutting or welding required
- Must be paired with off-road race tuning for proper performance
- Professional installation recommended for best results
- For off-road and race applications only
Frequently Asked Questions
Which years does this exhaust fit?
It's available in two versions: one for 2017–2019 and one for 2020–2026 Chevrolet Silverado and GMC Sierra 2500HD/3500HD trucks with the 6.6L Duramax L5P. Select the version that matches your truck's model year.
Should I choose the 4-inch or 5-inch system?
The 4-inch system suits trucks that tow and daily drive, with a slightly more restrained tone. The 5-inch system offers the most airflow and the deepest sound, making it ideal for built trucks and competition use.
What's the difference between the muffler options?
The No Muffler option is a straight-through pipe for maximum flow and volume. The With Muffler option adds a stainless steel muffler for a more controlled tone while keeping the race-style flow.
Does it require tuning?
Yes. Off-road race tuning is required for correct performance and to prevent error codes.
Are all components included?
Yes. Each kit includes stainless clamps, contour-bent hangers and improved flanges, plus the muffler when that option is selected.
Will it fit my Cab & Chassis truck?
No. This system fits EC, CC, SB, LB and Dually configurations but is not compatible with Cab & Chassis models.
2017-2019 GM 2500/3500HD Duramax L5P
2020-2026 GM 2500/3500HD Duramax L5P
2020-2026 GM 2500/3500HD Duramax L5P
Shipping Policy at Tuner Depot
At Tuner Depot, we understand the importance of timely delivery for your performance parts. We're committed to ensuring a seamless shipping experience, striving to dispatch your orders with utmost efficiency and speed.
Our Shipping Policy: Our aim is to dispatch all orders within two business days, providing you with a quick and efficient processing time. However, unforeseen circumstances beyond our control may occasionally impact shipping times.
Factors Affecting Shipping:
- Weather Conditions: Adverse weather conditions such as rain, snow, or sleet may affect delivery timelines. We will make every effort to minimize any delays.
- Holiday Periods: Please note that our shipping center will be closed during holidays. We will resume shipping promptly on the next business day. Allow for potential delays during peak seasons, but rest assured, we will keep you informed every step of the way.
- Staff Availability: Unforeseen circumstances can occasionally affect our staffing levels, possibly leading to minor delays. We are committed to swiftly resolving any issues to maintain our high standards of service.
We genuinely appreciate your understanding and patience during any unexpected obstacles. Be assured that we will utilize every resource available to deliver your performance parts promptly.
Items Eligible for Return
These items can be returned within 30 days of the purchase date, provided they are unopened, unused, and in their original packaging:
- Tuning devices – for example, an unopened/unused Mini Maxx V1/V2 or blank EFI Live Device
- Cables and device accessories – for example, an unopened/unused switch, bypass cable, universal pyrometer & docking station
Final Sale / Non-Refundable Items
The following items are final sale and cannot be returned:
- Custom tuning – including additional tune files purchased separately or custom tuning purchased with a device
- Exhausts and race pipes – this also includes downpipes purchased separately from an exhaust or race pipe
- EGR kits
Manufacturer Warranty
All items we sell include a 90-day manufacturer warranty.
If an item is being returned due to a manufacturer defect, it may be returned for a full refund, exchange, or replacement with a similar item of equal or lesser value.
For eligible items being returned for any other reason, the same options apply: full refund, exchange, or replacement with a similar item of equal or lesser value, provided the item meets the return requirements above.
Return Process
All returns must be approved by our team before being sent back. We will provide a valid RMA number and prepaid return label for the return.
Please do not send any items back without an approved RMA and the return label provided by us, as returns sent without these will not be accepted or processed.
Off-Road Use Only
These products are intended for off-road, race, and competition use only and may not be legal for use on public highways where emissions laws apply. Check your local and state regulations before purchase.
Customer Reviews
Overall rating: 4.6 / 5 from 179 reviews.
Fitment wasn’t the greatest could improve a lot
6.6L Duramax L5P 5 Inch Downpipe-Back Exhaust System | 2017–2026
Tuner depot was very helpful I thought I screwed up on the tune part and flashing the ecm but there customer service told me I didn’t mess it up and helped me through it but one thing for sure is nothing to do with tuner depot but no one every tells you on a first time doing one of these trucks the amount of hours it takes it took me almost 30 hours which if I had the right tools and confidence I could of probably cut it down to about 20 but kit works great it’s got awesome power now and I’ll be doing the down pipe very soon to I highly recommend just buying it and getting it over with because the truck is still very quiet almost like it’s a notch above stock
GM Duramax L5P All-In-One DPF/DEF/EGR Delete Kit (2017-2025)
Just got them installed on my truck yesterday and cannot believe the increase in performance! Can’t wait to take it on a road trip already see more power increase and fuel mileage. Unbelievable would do it again tomorrow!
Love the sound of the straight exhaust especially on the Dirtymax they just sound badass without a muffler
I purchased the efi live sotf tunes along with Dpf delete kit, dpf was good quality, tuner worked with me and not only sent my autocal loaded with a sotf tune but also sent me a few single tunes to use until I installed the switch, the only negative was that 130hp was the max power tune single or switch on the fly, but over all I was pretty happy and service was very good throughout.
The ordering process was easy, the parts came fast and the response from the team has been incredible!
6.6L Duramax L5P 5 Inch Downpipe-Back Exhaust System | 2017–2026
Love it
still waiting
nice sound without drawing unwanted attention
6 weeks was to long without updates
6.6L Duramax L5P Cold Air Intake | 2017-2026 Sierra/ Silverado
Very easy to work with! Everything fit as it should
6.6L Duramax L5P 5 Inch Downpipe-Back Exhaust System | 2017–2026
Pretty easy to install, works great
Works s expected
Great product
Timely delivery, great product NOT cheap junk.
L5P Downpipe 3.5 Inch Turbo Direct Pipe | 2017-2026 GMC Chevrolet
Thank you!
Great communication
Sounds great easy installation
6.6L Duramax L5P 5 Inch Downpipe-Back Exhaust System | 2017–2026
Did not fix on the fling correctly where the downpipe sits and was pushing upwards towards frame
6.6L Duramax L5P CAT & DPF Delete Pipe | 2017–2026 GMC/Chevy
Pretty straight forward install
6.6L Duramax L5P 5 Inch Downpipe-Back Exhaust System | 2017–2026
Helped quiet down the straight 4" pipe
Should come with clamps
Everything went smooth and lined up great just wish it would’ve came with instructions
6.6L Duramax L5P 5 Inch Downpipe-Back Exhaust System | 2017–2026
Customer service absolutely sucks!!!!
Great product
L5P Downpipe 3.5 Inch Turbo Direct Pipe | 2017-2026 GMC Chevrolet
Worked and fit as expected
Perfect sound
Could have come with some kind of directions. Made it through it ok but a little direction would have been nice. Overall everything works as it should.
Sounds great not to loud
Before installing never had a code after install getting low fuel rail pressure code under load. If I keep RPMs up just a little ( by switching to manual shift and never come out of 5 gear Allison 6 speed trans) will work fine . If u shift to 6th gear lower RPM as soon as u go up a little incline it starves for fuel and goes into reduced power mode. But if u mash the excelsior and down shifts it will take off like a rocket.
Worked perfectly.
6.6L Duramax L5P 5 Inch Downpipe-Back Exhaust System | 2017–2025
Sounds good.
I received a product that was very different from what I ordered, and I have tried to contact you but haven't received a response.
6.6L Duramax L5P Cold Air Intake | 2017-2026 Sierra/ Silverado
Truck has a nice rumble but not excessively load like a straight pipe.
Muffler has great sound, no restrictions. The best part of the whole deal was the outstanding service and shipping that Tuner Depot provided. Would definitely use them again.
Fit was very good and looks great on my vehicle.
6.6L Duramax L5P 5 Inch Downpipe-Back Exhaust System | 2017–2025
Sound is exactly what I was looking for.
Was a little nervous if it was going to show up, nice quality and ease of install would purchase again
GM Duramax 6.6L - Shibby Engineering Tuner Harness Plug Kit (2011-2023)
Excellent
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