6.6L Duramax L5P Downpipe 3.5 Inch Turbo Direct Pipe | 2017-2026 GMC Chevrolet
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6.6L Duramax L5P Downpipe 3.5 Inch Turbo Direct Pipe | 2017-2026 GMC Chevrolet
SKU: SKU:EP-GM-L5P-DP
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This L5P downpipe is a 3.5' turbo direct downpipe made for 2017-2026 GM Duramax 6.6L L5P pickup trucks. It bolts directly to the turbocharger and replaces the factory downpipe that contains the DOC (Diesel Oxidation Catalyst) filter.
Removing the DOC right after the turbo allows exhaust gases to flow out faster. This helps the turbo spool quicker, reduces exhaust restriction and improves overall engine performance. This downpipe is commonly used on off-road and competition trucks where maximum exhaust flow is needed.
| Pipe Diameter | 3.5 inches |
| Material | High-grade T409 stainless steel |
| Flange Style | 4-bolt turbo flange |
| Studs | Two pre-installed turbo studs |
| Finish | Raw stainless with heat wrap included |
| Design | Turbo-direct DOC delete downpipe |
| Year | Make | Model | Engine | Body Type |
|---|---|---|---|---|
| 2017 | Chevrolet | Silverado 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2018 | Chevrolet | Silverado 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2019 | Chevrolet | Silverado 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2020 | Chevrolet | Silverado 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2021 | Chevrolet | Silverado 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2022 | Chevrolet | Silverado 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2023 | Chevrolet | Silverado 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2024 | Chevrolet | Silverado 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2025 | Chevrolet | Silverado 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2026 | Chevrolet | Silverado 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2017 | GMC | Sierra 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2018 | GMC | Sierra 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2019 | GMC | Sierra 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2020 | GMC | Sierra 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2021 | GMC | Sierra 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2022 | GMC | Sierra 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2023 | GMC | Sierra 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2024 | GMC | Sierra 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2025 | GMC | Sierra 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
| 2026 | GMC | Sierra 2500HD / 3500HD | 6.6L Duramax L5P | Pickup Truck |
On GM L5P Duramax engines, the DOC is positioned immediately after the turbocharger. While necessary for emissions compliance, it creates a major restriction in the exhaust path. Installing an aftermarket L5P downpipe is the primary method to remove this restriction at its source.
A larger 3.5' Duramax down pipe allows exhaust gases to exit the turbo more efficiently, reducing backpressure while improving throttle response, turbo sound and engine efficiency. This modification is commonly performed as part of a complete L5P delete exhaust system intended for off-road or competition use.
Because the DOC is an emissions-controlled component, professional custom tuning is required after installation to prevent check engine lights and ensure proper engine operation. This product is not emissions compliant and is not legal for street-driven vehicles.
It replaces the factory turbo outlet pipe and removes the L5P DOC to improve exhaust flow and turbo response.
Yes. Most delete exhaust systems do not remove the DOC. This downpipe is required to fully eliminate it.
Yes, without proper tuning. Professional custom tuning is required after installation.
No. This product removes emissions equipment and is intended for off-road use only.
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:
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.
These items can be returned within 30 days of the purchase date, provided they are unopened, unused, and in their original packaging:
The following items are final sale and cannot be returned:
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.
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.
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.
Overall rating: 4.5 / 5 from 197 reviews.
Exhaust was too short, customer service eventually just quit responding after sending picture after picture of it being too short. The exhaust rubs on the transmission hanger bracket so I had to remove and cut that down. I would not buy this kit unless you want to spend extra time modifying it.
6.6L Duramax L5P CAT & DPF Delete Pipe | 2017–2026 GMC/Chevy
It’s more responsive in the pedal.
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.
Thing is built really nice ain’t no cheap junk
6.6L Duramax L5P Downpipe 3.5 Inch Turbo Direct Pipe | 2017-2026 GMC Chevrolet
There were no directions/tips for R&I for the muffler or delete pipe. I get that it's not rocket science, but you should get SOME help for $2K! All of the information that I did receive was in a time limited email hyperlink that of course, is now expired. I reached out to support and have never heard back from them. I will spend my hard-earned money elsewhere in the future. Customer service is very poor.
Works good so far
Tunes are not working. We are on the 3rd tune and truck is running like garbage. Hopefully the 4th tune file will fix the issues.
As described and shipped quickly.
Worked like a champ
Takes some time but help from support was appreciated
Needs better instructions for install but it was quality parts.
Not sure I like the hanger options but it sounds good and was simple to install.
6.6L Duramax L5P 5 Inch Downpipe-Back Exhaust System | 2017–2026
Fits well.
Easy to install. Could use a printed copy of the installation procedure.
6.6L Duramax L5P Downpipe 3.5 Inch Turbo Direct Pipe | 2017-2026 GMC Chevrolet
Fit great.
Purchase multiple things from these guys always on time and great quality!
All good, just wished it came with down pipe.
6.6L Duramax L5P 5 Inch Downpipe-Back Exhaust System | 2017–2026
Easy install and like how it works.
Quality parts.
Delete kit was as it should be, only thing I’d say is the hardware is cheap and should come with bolts that can withstand heat so if a person ever had to remove them they won’t break. Also they don’t volunteer install directions which are super nice to have if you’ve never done one of these. I had to ask several times for the delete, ez lynk, and cam buss plug directions.
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
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