Stainless Steel Diesel Muffler
4-Inch
304 Stainless Steel
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Stainless Steel Diesel Muffler
SKU: SKU:MUF-SS-4-S3
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This stainless steel diesel muffler is a straight-through performance muffler for diesel trucks. It reduces back pressure and gives your truck a deep, throaty exhaust note. Choose a 4-inch diesel muffler or 5-inch diesel muffler to match your exhaust, then pick 304 or 409 stainless steel. It fits Cummins, Duramax, and Powerstroke trucks and pairs with our complete diesel straight exhaust systems.
This diesel truck muffler comes in four combinations, so you can match your exhaust pipe and choose the steel grade that suits your climate and budget.
Match the muffler to your existing exhaust pipe diameter for the cleanest fit and consistent flow.
Both grades share the same straight-through design and dimensions.
| Feature | 304 Stainless Steel | 409 Stainless Steel |
|---|---|---|
| Corrosion Resistance | Higher (more chromium plus nickel) | Good (lower chromium, no nickel) |
| Appearance Over Time | Keeps its finish longer | May develop surface discoloration |
| Price | Premium | More economical |
| Best For | Road salt, wet climates, visible installs | Value-focused builds and drier climates |
A muffler on a diesel engine controls exhaust noise and shapes the sound of your truck. Factory mufflers use chambers and baffles that can add back pressure. A straight-through diesel muffler uses a perforated core instead, so exhaust gas flows freely while internal mesh and fiberglass packing absorb unwanted resonance.
The result is a diesel exhaust muffler that helps your truck breathe easier and sound richer, without the harsh drone of a straight pipe.
| Specification | 4-Inch Diesel Muffler | 5-Inch Diesel Muffler |
|---|---|---|
| Inlet Size | 4-inch inner diameter | 5-inch inner diameter |
| Outlet Size | 4-inch inner diameter | 5-inch inner diameter |
| Overall Length | 20.5 inches | 20.5 inches |
| Material Options | 304 or 409 stainless steel | 304 or 409 stainless steel |
| Flow Design | Straight-through, non-directional | Straight-through, non-directional |
Every feature is designed to improve airflow and sound quality:
This multi-fitment diesel truck muffler fits a wide range of diesel vehicles, including Cummins, Duramax, and Powerstroke trucks. It works on both classic and late-model diesel trucks, as long as the inlet and outlet size matches your exhaust. Use the vehicle selector on this page to confirm fitment.
Installation is seamless with Black Bandit Exhaust Systems, which come with pre-bent and pre-welded hangers.
A straight-through muffler sits between a full straight pipe and a stock exhaust. It keeps strong flow while controlling drone.
| Option | Sound | Flow | Best For |
|---|---|---|---|
| Straight-Through Performance Muffler | Deep, throaty tone with reduced resonance | Low back pressure | Performance with a controlled, aggressive sound |
| Straight Pipe / Muffler Delete | Loudest, often with cabin drone | Unrestricted | Maximum volume where local laws allow it |
| Resonator Only | Targets specific drone frequencies | Low restriction | Fine-tuning tone alongside a muffler |
Get a complete, high-flow diesel exhaust in one order. Start with this muffler and add matching components in our kit builder:
The muffler is non-directional, so it can be installed in either direction. It is designed to directly replace a muffler-delete pipe of the same diameter.
A muffler controls exhaust noise and helps keep a diesel truck within acceptable sound levels. Many states and provinces have vehicle noise and exhaust equipment rules, so check your local regulations. A straight-through performance muffler keeps strong exhaust flow while still controlling harsh noise and drone.
Match the muffler to your exhaust pipe diameter. A 4-inch exhaust system takes the 4-inch diesel muffler, and a 5-inch system takes the 5-inch diesel muffler. Both are 20.5 inches long overall body.
304 stainless steel is better for road salt, wet weather, or keeping a clean finish longer. 409 stainless steel is a durable, more economical exhaust-grade option. Both versions share the same straight-through design and dimensions.
Yes. The muffler fits Cummins, Duramax, and Powerstroke diesel trucks, both classic and late model, as long as the inlet and outlet size matches your exhaust system. Use the vehicle selector on this page to confirm fitment.
It produces a rich, throaty exhaust note. The internal mesh and fiberglass absorb interior resonance, so the tone is deeper and fuller than a straight pipe.
No. The muffler has a non-directional design, so it can be installed in either direction.
No. The muffler does not include hardware. You may need to weld it in or supply your own clamps if your exhaust system does not have a muffler-delete pipe it can directly replace.
Yes. If your exhaust system has a muffler-delete pipe of the matching diameter, this muffler is designed to directly replace it.
Most builds pair this muffler with a straight diesel exhaust system in the matching diameter and a stainless exhaust tip. Off-road and competition builds may also add a DPF delete pipe.
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: 4.6 / 5 from 195 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.
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
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
