Walker 55557 Catalytic Converter - Left

Brand Walker 55557
Position Left
Mounting Hardware Included No
Universal Or Specific Fit Specific
Grade Type Regular
Body Height 4.25
Body Length 10
Body Width 6
Inlet Quantity 1
Body Material Stainless steel
Outlet Quantity 1
California Air Resources Board (CARB) Certified No
Overall Length 50
Air Tube No
Air Tube Count No
Body Height 4.250
Body Length 10.000
Body Material Stainless steel
Body Shape Small oval
Body Width 6.000
Converter Quantity 1
Fitment Direct fit
Inlet 1 Type 3 bolt welded flange
Inlet Connection Type 3 bolt welded flange
Inlet Count 1
Inlet Type 3 bolt welded flange
Max Year Covered 2007
Min Year Covered 2003
Most Popular Make / Model Chevrolet silverado 2500 hd
Most Popular Year 2004
Outlet 1 Outside Diameter 3
Outlet 1 Type Pipe connection
Product line EPA
Fits Chevrolet and GMC · 38 vehicles

Direct-fit replacement. Specific fit and welded flange connections simplify installation.

Stainless steel body. Resists corrosion for dependable exhaust service.

Ceramic substrate. Helps deliver efficient catalytic performance.

Cross-references Anchor 9223, AP Exhaust 645455 and Eastern Catalytic 50423 for the same application. See all 10.

$448.51Free shipping
In stock · usually ships same day before 1pm CST
Step 1 — Confirm fitment
Free return shipping if it doesn't fit when you check fitment here first.

Select your vehicle to confirm fitment
Verify this part fits before purchasing โ€” free returns if it doesn't
Step 2 — Quantity
Order total $448.51
Free shipping to the continental U.S.
Free returns within 60 days if it doesn't fit when fitment is verified.

Walker EPA 55557 Catalytic Converter

Walker EPA 55557 is a direct-fit catalytic converter for select 2003-2007 Chevrolet Silverado and GMC Sierra trucks with Federal Emission systems. It uses a stainless steel body, a ceramic substrate, and OE-style inlet and outlet connections for a precise replacement on the left side.

Key Features

  • Direct-fit design for specific applications
  • Stainless steel body with small oval housing
  • Ceramic substrate material
  • 1 inlet and 1 outlet
  • 3-bolt welded flange inlet and 3-inch pipe connection outlet
  • Pre- and post-catalyst oxygen sensor locations
  • EPA-compliant product line for OBDII vehicles
  • Part number: 55557

Product Details

Walker EPA 55557 is part of the Walker Ultra Direct-Fit Catalytic Converter line, built for import and domestic OBDII vehicles from 1996 and newer. This converter is engineered for specific truck applications and follows EPA standards, making it a practical replacement for emissions-system service on a Chevrolet Silverado 2500 HD, Silverado 3500, Silverado 3500 Classic, GMC Sierra 2500 HD, Sierra 3500, and Sierra 3500 Classic. The unit measures 50 inches overall, with a 10-inch body length, 6-inch body width, and 4.25-inch body height.

This part cross-references Eastern Catalytic 50423 for the same application.

Vehicle Fitment

  • Fits 2007 Chevrolet Silverado 3500 Classic, left, with Federal Emission System; not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Exhaust gasket is recommended.
  • Fits 2007 GMC Sierra 3500 Classic, left, with Federal Emission System; not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Exhaust gasket is recommended.
  • Fits 2003-2006 Chevrolet Silverado 2500 HD, left, with Federal Emission System; except Low Emission Vehicle (LEV). Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Exhaust gasket is recommended.
  • Fits 2003-2006 Chevrolet Silverado 3500, left, with Federal Emission System; not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Exhaust gasket is recommended.
  • Fits 2003-2006 GMC Sierra 2500 HD, left, with Federal Emission System; except Low Emission Vehicle (LEV). Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Exhaust gasket is recommended.
  • Fits 2003-2006 GMC Sierra 3500, left, with Federal Emission System; not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Exhaust gasket is recommended.
  • Fits 2004 Chevrolet Silverado 2500, left, with Federal Emission System; except Low Emission Vehicle (LEV). Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Exhaust gasket is recommended.
  • Fits 2004 GMC Sierra 2500, left, with Federal Emission System; except Low Emission Vehicle (LEV). Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Exhaust gasket is recommended.

Installation Notes

Confirm Federal Emission system coverage before ordering, since this converter is not CARB certified. The 3-bolt welded flange inlet and pipe-style outlet are designed for direct replacement, and an exhaust gasket is recommended during installation. Verify oxygen sensor placement at both pre- and post-catalyst locations before final assembly.

Quality Assurance

Walker EPA 55557 is built to meet EPA standards for the listed applications and is part of Walkerโ€™s Ultra Direct-Fit line for OBDII vehicles. The stainless steel construction and application-specific fitment support consistent replacement quality for the covered Chevrolet Silverado and GMC Sierra models.

This part fits 38 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelLitersCylindersWheel BasePositionNotes
2007ChevroletSilverado 3500 Classic6.0LV8133.0"Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2007ChevroletSilverado 3500 Classic8.1LV8133.0"Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2007GMCSierra 3500 Classic8.1LV8133.0"Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2007GMCSierra 3500 Classic6.0LV8133.0"Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2006ChevroletSilverado 2500 HD6.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2006ChevroletSilverado 2500 HD8.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2006ChevroletSilverado 35008.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2006ChevroletSilverado 35006.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2006GMCSierra 2500 HD6.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2006GMCSierra 2500 HD8.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2006GMCSierra 35008.1LV8—Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2006GMCSierra 35006.0LV8—Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2005ChevroletSilverado 2500 HD6.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2005ChevroletSilverado 2500 HD8.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2005ChevroletSilverado 35008.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2005ChevroletSilverado 35006.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2005GMCSierra 2500 HD6.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2005GMCSierra 2500 HD8.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2005GMCSierra 35008.1LV8—Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2005GMCSierra 35006.0LV8—Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2004ChevroletSilverado 25006.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2004ChevroletSilverado 2500 HD6.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2004ChevroletSilverado 2500 HD8.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2004ChevroletSilverado 35008.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2004ChevroletSilverado 35006.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2004GMCSierra 25006.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2004GMCSierra 2500 HD6.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2004GMCSierra 2500 HD8.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2004GMCSierra 35008.1LV8—Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2004GMCSierra 35006.0LV8—Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2003ChevroletSilverado 2500 HD6.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2003ChevroletSilverado 2500 HD8.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2003ChevroletSilverado 35008.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2003ChevroletSilverado 35006.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2003GMCSierra 2500 HD6.0LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2003GMCSierra 2500 HD8.1LV8—Leftwith Federal Emission System; except Low Emission Vehicle (LEV); Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2003GMCSierra 35008.1LV8—Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
2003GMCSierra 35006.0LV8—Leftwith Federal Emission System; Not legal for sale or use in California and other CARB-compliant states. Legal in New York and Maine on EPA Federal Emission Equipped Vehicles only. Consult the aftermarket converter regulations in your state for details.; Exhaust Gasket is Recommended; Ultra Direct Fit Type; EPA
Directly replaces or cross-references 10 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
Anchor — 9223AP Exhaust — 645455Eastern Catalytic — 50423Four Seasons — 54719Gates — 24457496434964693480645782645818