Walker 18963 Exhaust Muffler - Front
OE Quality 60-Day Returns
Walker
 SoundFX Direct Fit

Walker 18963 Exhaust Muffler - Front

Brand Walker 18963
Position Front
Muffler Type Reflection
Universal Or Specific Fit Specific
Shape Oval
Grade Type Regular
Inlet Inside Diameter 1.75
Body Width 11
Outlet Quantity 1
Reversible No
Tunable No
Overall Length 39.5
Body Height 5.5
Body Length 18
Body Material Steel
Finish Aluminized
Inlet 1 Inside Diameter 1.75
Inlet 1 Type Pipe connection
Inlet 2 Inside Diameter 1.75
Inlet 2 Type Pipe connection
Inlet Configuration Dual
Inlet Offset 1.5
Inlet Quantity 2
Inlet Type Pipe connection
Outlet 1 Type 2 bolt welded flange
Outlet Configuration Offset
Outlet Type 2 bolt welded flange
Product line SoundFX Direct Fit
Fits INFINITI and Nissan · 7 vehicles

Direct-fit design. Installs as a specific replacement with no guesswork.

Aluminized steel. Helps resist corrosion for longer service life.

Reflection muffler. Engineered for quality appearance and favorable acoustics.

Cross-references AP Exhaust 7450 for the same application. See all 1.

$119.34Free 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 — free returns if it doesn't
Step 2 — Quantity
Order total $119.34
Free shipping to the continental U.S.
Free returns within 60 days if it doesn't fit when fitment is verified.
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Walker SoundFX Direct Fit Muffler for Pathfinder and QX4

Walker SoundFX Direct Fit muffler Part Number 18963 is a specific-fit exhaust muffler for select 2001-2004 Nissan Pathfinder and 2001-2003 INFINITI QX4 front applications. It uses an oval steel body with aluminized finish to support longer service life than low-carbon steel while maintaining a clean OE-style appearance and controlled exhaust acoustics.

Key Features

  • Specific-fit exhaust muffler for direct replacement applications
  • Oval reflection-style muffler construction
  • 100% aluminized steel body for improved corrosion resistance
  • Mechanical interior joints and spun-locked heads for added durability
  • Dual 1.75 in. pipe connection inlets with offset outlet configuration
  • 2-bolt welded flange outlet type
  • Walker SoundFX Direct Fit product line for OE-style exhaust service

Detailed Product Overview

Walker 18963 is built for drivers servicing the exhaust system on a Nissan Pathfinder or INFINITI QX4 and need a direct-fit muffler with factory-style dimensions and connection points. The 39.5 in. overall length, 11 in. body width, and 5.5 in. body height support a precise underbody fit, while the aluminized steel construction helps the muffler stand up to everyday road exposure. This part cross-references AP Exhaust 7450 for the same application.

The SoundFX Direct Fit line focuses on replacement mufflers that match the vehicle’s original layout and acoustic profile. For 2001-2004 Nissan Pathfinder front exhaust service and 2001-2003 INFINITI QX4 front exhaust service, Part Number 18963 provides a practical OE-style solution without requiring a universal-fit workaround.

Common Exhaust Issues It Can Address

  • Exhaust noise from a worn or rusted muffler
  • Corrosion-related muffler failure in the front exhaust section
  • Restricted exhaust flow caused by internal deterioration
  • Fitment problems from using a universal muffler on a specific application
  • Loss of OE-style exhaust tone after muffler replacement

Installation Notes and Tips

Compatible With 2001-2004 Nissan Pathfinder, front, and 2001-2003 INFINITI QX4, front. If the vehicle uses a welded assembly, replace all required parts during service so the exhaust section aligns correctly. Verify inlet and outlet orientation before installation: dual 1.75 in. pipe connection inlets and an offset 2-bolt welded flange outlet.

Quality Assurance

Walker uses aluminized steel, mechanical interior joints, and spun-locked heads to support durability in everyday exhaust service. The SoundFX Direct Fit design is focused on consistent fit, OE-style appearance, and favorable acoustics for the listed Pathfinder and QX4 applications.

Related reading

This part fits 7 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelLitersCylindersPositionNotes
2004NissanPathfinder3.5LV6FrontIf welded assembly, replace all required parts; SoundFX Direct Fit
2003INFINITIQX43.5LV6FrontIf welded assembly, replace all required parts; SoundFX Direct Fit
2003NissanPathfinder3.5LV6FrontIf welded assembly, replace all required parts; SoundFX Direct Fit
2002INFINITIQX43.5LV6FrontIf welded assembly, replace all required parts; SoundFX Direct Fit
2002NissanPathfinder3.5LV6FrontIf welded assembly, replace all required parts; SoundFX Direct Fit
2001INFINITIQX43.5LV6FrontIf welded assembly, replace all required parts; SoundFX Direct Fit
2001NissanPathfinder3.5LV6FrontIf welded assembly, replace all required parts; SoundFX Direct Fit
Directly replaces or cross-references 1 part number
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
AP Exhaust — 7450