This is the product description text that will appear here.
Quantity
1
Description
The Universal 4" Optimal Flow Muffler fits any 4" aftermarket straight pipe exhaust system on Powerstroke, Cummins, and Duramax trucks. It's a straight-through, non-directional design built to knock down resonance without choking your flow.
...
Reviews
4.6
18 ratings
5
4
3
2
1
4” muffler
Installed the 4” muffler after deleting the truck without the muffler and was a little too loud towing and had a bit of a drone while cruising. The muffler solved everything. Thank you!
M
Mike · June 8, 2026
Works Great
Does a great job taking the edge off of you think the straight pipe is too loud. Installed easily and gives it a lower powerful growl.