Dynomax 21172 Exhaust Muffler
OE Quality 60-Day Returns
Dynomax
 Heavy Duty

Dynomax 21172 Exhaust Muffler

Brand Dynomax 21172
Automotive Item Grade Oem standard part
Body Length 15.000 in.
Body Width 9.000 in.
Finish Aluminized
Fitment Universal
Inlet Connection Type Pipe
Inlet Diameter Designation Inside diameter
Inlet Inside Diameter 4.000 in.
Inlet Position Center
Inlet Quantity 1
Inlet Type Single center
Main Piping Diameter 4.000 in.
Material Aluminized steel
Max Year Covered 2006
Min Year Covered 2001
Most Popular Make/Model Chevrolet silverado 2500 hd
Most Popular Year 2005
Muffler Body Finish Aluminized
Muffler Body Height 9.000 in.
Muffler Body Length 15.000 in.
Muffler Body Material Steel
Muffler Body Shape Round
Muffler Body Width 9.000 in.
Muffler Count 1
Muffler Inlet Diameter 4.000 in.
Muffler Outlet Diameter 4.000 in.
Muffler Overall Length 22.000 in.
Muffler Reversible No
Muffler Type Combination
Outlet Configuration Center
Product line Heavy Duty
Fits Chevrolet and GMC · 24 vehicles

OEM standard part. Built to match original equipment expectations for a straightforward replacement.

Aluminized steel. Helps resist corrosion while keeping the muffler durable in demanding use.

Round combination design. Delivers a versatile exhaust muffler layout for broad application coverage.

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Not what you need? See all Exhaust Muffler options

Heavy Duty Exhaust Muffler for HD Trucks

The Dynomax Heavy Duty 21172 is a universal exhaust muffler built with aluminized steel construction and a round body for demanding truck applications. With 4-inch inlet and outlet sizing, it supports heavy-duty exhaust routing for select Chevrolet Silverado 2500 HD and GMC Sierra HD platforms from 2001-2006.

Key Features

  • Dynomax Heavy Duty part number 21172
  • Universal fitment with 4.000 in. inlet and 4.000 in. outlet
  • Aluminized steel material with aluminized finish
  • Round muffler body measuring 15.000 in. long and 9.000 in. wide
  • Overall length of 22.000 in. with center inlet and center outlet
  • Combination muffler type for heavy-duty exhaust applications
  • OEM Standard Part grade with economy product grade

Product Details

This Dynomax Heavy Duty muffler is built for truck owners who need a direct exhaust component with common 4-inch piping dimensions. The aluminized steel body helps resist corrosion in working environments, while the round, center-inlet, center-outlet layout supports straightforward exhaust routing. Part number 21172 is listed for 2001-2006 Chevrolet Silverado 2500 HD, 2001-2006 Chevrolet Silverado 3500, 2001-2006 GMC Sierra 2500 HD, and 2001-2006 GMC Sierra 3500 heavy-duty applications.

Dynomax Heavy Duty focuses on replacement exhaust components for hard-working on-road and off-road commercial vehicles. This muffler follows that approach with broad coverage and OE-style sizing for common HD truck exhaust systems. This part cross-references Walker (e.g., 21172) for the same application.

Common Issues This Part Can Address

  • Damaged or rusted muffler housing on heavy-duty trucks
  • Restricted exhaust flow from a worn internal muffler core
  • Exhaust noise caused by a failing factory muffler
  • Replacement needs for 4-inch inlet and outlet exhaust systems
  • Corrosion-related exhaust service on work trucks

Installation Notes and Tips

Verify inlet and outlet diameter, center-in/center-out routing, and overall length before installation. Confirm vehicle-specific exhaust layout on 2001-2006 Chevrolet Silverado 2500 HD, Chevrolet Silverado 3500, GMC Sierra 2500 HD, and GMC Sierra 3500 models to ensure proper alignment with existing piping. Professional exhaust installation is recommended for accurate fitment and secure sealing.

Quality Assurance

Dynomax Heavy Duty exhaust components are built for replacement use in demanding truck applications and are specified here with aluminized steel construction and OEM Standard Part grading. Part number 21172 is cataloged for broad heavy-duty vehicle coverage, including Chevrolet Silverado 2500 HD and GMC Sierra HD fitments.

Related reading

This part fits 24 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelSubmodelLitersCylindersWheel BasePositionNotes
2006ChevroletSilverado 2500 HD—6.6LV8133.0"N/AHeavy Duty
2006ChevroletSilverado 3500—6.6LV8133.0"N/AHeavy Duty
2006GMCSierra 2500 HD—6.6LV8133.0"N/AHeavy Duty
2006GMCSierra 3500—6.6LV8133.0"N/AHeavy Duty
2005ChevroletSilverado 2500 HD—6.6LV8133.0"N/AHeavy Duty
2005ChevroletSilverado 3500—6.6LV8133.0"N/AHeavy Duty
2005GMCSierra 2500 HD—6.6LV8133.0"N/AHeavy Duty
2005GMCSierra 3500—6.6LV8133.0"N/AHeavy Duty
2004ChevroletSilverado 2500 HDBase6.6LV8133.0"N/AHeavy Duty
2004ChevroletSilverado 3500—6.6LV8133.0"N/AHeavy Duty
2004GMCSierra 2500 HD—6.6LV8133.0"N/AHeavy Duty
2004GMCSierra 3500—6.6LV8133.0"N/AHeavy Duty
2003ChevroletSilverado 2500 HD—6.6LV8133.0"N/AHeavy Duty
2003ChevroletSilverado 3500—6.6LV8133.0"N/AHeavy Duty
2003GMCSierra 2500 HD—6.6LV8133.0"N/AHeavy Duty
2003GMCSierra 3500—6.6LV8133.0"N/AHeavy Duty
2002ChevroletSilverado 2500 HD—6.6LV8133.0"N/AHeavy Duty
2002ChevroletSilverado 3500—6.6LV8133.0"N/AHeavy Duty
2002GMCSierra 2500 HD—6.6LV8133.0"N/AHeavy Duty
2002GMCSierra 3500—6.6LV8133.0"N/AHeavy Duty
2001ChevroletSilverado 2500 HD—6.6LV8133.0"N/AHeavy Duty
2001ChevroletSilverado 3500—6.6LV8133.0"N/AHeavy Duty
2001GMCSierra 2500 HD—6.6LV8133.0"N/AHeavy Duty
2001GMCSierra 3500—6.6LV8133.0"N/AHeavy Duty