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Walker Heavy Duty 21172 Direct Fit Exhaust Muffler 4' Inlet (ID) 4' Outlet (ID)

Free shipping on orders over $29.99

$126.02

$ 60 .99 $60.99

In Stock

About this item

  • COMPATIBILITY – Universal fit, check product dimensions
  • GET THE RIGHT PART -- Before purchasing, research to ensure that the part will fit your vehicle; enter all vehicle information (year, make, model, engine and trim) for compatibility and check qualifier notes
  • Manufactured from aluminized steel for durability
  • Designed to help ensure long service life
  • Engineered to reduce in-cab and exterior engine noise
  • Offered in a variety of styles, sizes and materials for your installation needs
  • An economical replacement for the original equipment part


Walker offers hundreds of muffler designs and styles to fit virtually any hard-working on/off road commercial vehicle. Walker is a "one-stop" convenience, offering complete engine-to-tailpipe coverage of replacement emissions control systems and components for popular domestic, import and commercial vehicle applications.


G. Hunt
Reviewed in the United States on November 7, 2008
If you are buying this muffler expecting a perforated core, fiberglass packed straight through style of muffler like ALL the other Ultra-Flo mufflers, take note: It isn't.This muffler is one of the stranger ones I've ever seen. On either end of the muffler, right inside the inlets, there is a short perforated section, maybe 4" long or so. These sections are surrounded by fiberglass packing.Beyond this, however, in the center of the muffler, it just opens up into a very large, open chamber with nothing in it.Whether this open area is supposed to act as a resonator of some sort, I really don't know. What I do know is that this muffler does very little muffling.So, if you're looking for a loud muffler, this will do the trick. But then, if you're looking for a loud muffler, you're probably not looking for some huge bulky muffler like this thing, are you? If you're looking for a quiet muffler (like I was), keep looking, because this isn't it.