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SoundFX Direct Fit

Walker 18187 Exhaust Muffler

Brand	Walker 18187
Universal Or Specific Fit	Specific
Shape	Oval
Grade Type	Regular
Inlet Inside Diameter	2.25
Body Width	9.75
Inlet Quantity	1
Outlet Quantity	1
Reversible	No
Tunable	No
Overall Length	31.75
Body Height	4.25
Body Length	21
Body Material	Steel
Finish	Aluminized
Inlet 1 Inside Diameter	2.25
Inlet 1 Type	Pipe connection
Inlet Configuration	Offset
Inlet Offset	2.875
Inlet Type	Pipe connection
Muffler Type	Combination
Outlet 1 Outside Diameter	2
Outlet 1 Type	Tip
Outlet Configuration	Center
Outlet Outside Diameter	2
Outlet Type	Tip
Product line	SoundFX Direct Fit
Fits	Chevrolet and GMC · 112 vehicles

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

Aluminized steel. Helps resist corrosion for longer service life than low-carbon steel.

Mechanical interior joints. Spun-locked heads add durability and help maintain a quality appearance.

Cross-references AMS Automotive 6590 and AP Exhaust 700020 for the same application. See all 2.

$65.96Free shipping

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Walker SoundFX Direct Fit Muffler for S10 and S15

Walker SoundFX Direct Fit muffler Part Number 18187 is a specific-fit exhaust muffler for select Chevrolet S10 and GMC S15 applications. It uses an oval steel body with an 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 muffler body with aluminized steel construction
1 inlet and 1 outlet with pipe connection inlet design
Offset inlet configuration and center outlet configuration
Mechanical interior joints and spun-locked heads for added durability
Combination muffler design for balanced exhaust tone
Part Number 18187 for catalog and fitment lookup

Product Line Details

Walker SoundFX Direct Fit is the Walker muffler line focused on replacement fitment, consistent appearance, and controlled sound levels. For drivers replacing a worn exhaust on a Chevrolet S10 or GMC S15, this line is built to match the vehicle-specific layout while using aluminized steel construction for improved corrosion resistance compared with low-carbon steel alternatives.

Detailed Description

Walker 18187 is a direct-fit exhaust muffler with a 2.25-inch inlet inside diameter, 2-inch outlet outside diameter, 31.75-inch overall length, 21-inch body length, 9.75-inch body width, and 4.25-inch body height. The offset inlet and center outlet layout supports the factory-style routing used on the listed Chevrolet S10 and GMC S15 applications. This part cross-references AP Exhaust 700020 for the same application.

Vehicle Fitment

Fits 1982 Chevrolet S10, N/A
Fits 1983-1991 Chevrolet S10, N/A; if welded assembly, replace all required parts; SoundFX Direct Fit
Fits 1982 GMC S15, N/A
Fits 1983-1990 GMC S15, N/A; if welded assembly, replace all required parts; SoundFX Direct Fit
Fits 1991 GMC Sonoma, N/A; if welded assembly, replace all required parts; SoundFX Direct Fit

Common Replacement Reasons

Exhaust noise from a rusted or damaged muffler
Loss of factory-style exhaust tone control
Corrosion on an original steel muffler body
Need for a direct-fit replacement on Chevrolet S10 or GMC S15 trucks
Repair of a welded exhaust assembly with a vehicle-specific muffler

Installation Notes

Verify inlet and outlet orientation before installation, especially on welded exhaust assemblies. Confirm the 2.25-inch inlet and 2-inch outlet dimensions against the existing exhaust routing on the vehicle. For the listed Chevrolet S10, GMC S15, and GMC Sonoma applications, match the factory layout and replace all required exhaust components when the system is welded together.

Quality Assurance

Walker uses 100% aluminized steel in this SoundFX Direct Fit muffler to improve service life, and the mechanical interior joints plus spun-locked heads are used to support durability in everyday exhaust service.

This part fits 112 vehicles

Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.

Year	Make	Model	Drive Type	Liters	Cylinders	Wheel Base	Position	Notes
1991	Chevrolet	S10	4WD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1991	Chevrolet	S10	RWD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1991	Chevrolet	S10	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1991	Chevrolet	S10	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1991	Chevrolet	S10	4WD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1991	GMC	Sonoma	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1991	GMC	Sonoma	4WD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1991	GMC	Sonoma	4WD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1990	Chevrolet	S10	4WD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1990	Chevrolet	S10	RWD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1990	Chevrolet	S10	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1990	Chevrolet	S10	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1990	Chevrolet	S10	4WD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1990	GMC	S15	4WD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1990	GMC	S15	RWD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1990	GMC	S15	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1990	GMC	S15	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1990	GMC	S15	4WD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1989	Chevrolet	S10	4WD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1989	Chevrolet	S10	RWD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1989	Chevrolet	S10	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1989	Chevrolet	S10	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1989	Chevrolet	S10	4WD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1989	GMC	S15	4WD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1989	GMC	S15	RWD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1989	GMC	S15	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1989	GMC	S15	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1989	GMC	S15	4WD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	Chevrolet	S10	4WD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	Chevrolet	S10	RWD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	Chevrolet	S10	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	Chevrolet	S10	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	Chevrolet	S10	4WD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	Chevrolet	S10	4WD	2.5L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	GMC	S15	4WD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	GMC	S15	RWD	4.3L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	GMC	S15	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	GMC	S15	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	GMC	S15	4WD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1988	GMC	S15	4WD	2.5L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1987	Chevrolet	S10	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1987	Chevrolet	S10	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1987	Chevrolet	S10	4WD	2.5L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1987	Chevrolet	S10	4WD	2.8L	V6	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1987	GMC	S15	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1987	GMC	S15	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1987	GMC	S15	4WD	2.8L	V6	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1987	GMC	S15	4WD	2.5L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1986	Chevrolet	S10	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1986	Chevrolet	S10	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1986	Chevrolet	S10	4WD	2.5L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1986	Chevrolet	S10	4WD	2.8L	V6	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1986	GMC	S15	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1986	GMC	S15	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1986	GMC	S15	4WD	2.8L	V6	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1986	GMC	S15	4WD	2.5L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	Chevrolet	S10	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	Chevrolet	S10	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	Chevrolet	S10	RWD	1.9L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	Chevrolet	S10	RWD	2.2L	L4	108.4"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	Chevrolet	S10	4WD	1.9L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	Chevrolet	S10	4WD	2.5L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	Chevrolet	S10	RWD	2.2L	L4	122.9"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	Chevrolet	S10	4WD	2.8L	V6	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	Chevrolet	S10	RWD	2.2L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	GMC	S15	RWD	1.9L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	GMC	S15	RWD	2.5L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	GMC	S15	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	GMC	S15	4WD	2.8L	V6	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	GMC	S15	4WD	1.9L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	GMC	S15	RWD	2.2L	L4	122.9"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	GMC	S15	RWD	2.2L	L4	108.4"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	GMC	S15	RWD	2.2L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1985	GMC	S15	4WD	2.5L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	Chevrolet	S10	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	Chevrolet	S10	RWD	2.0L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	Chevrolet	S10	RWD	1.9L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	Chevrolet	S10	RWD	2.2L	L4	108.4"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	Chevrolet	S10	4WD	1.9L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	Chevrolet	S10	4WD	2.0L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	Chevrolet	S10	RWD	2.2L	L4	122.9"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	Chevrolet	S10	4WD	2.8L	V6	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	Chevrolet	S10	RWD	2.2L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	GMC	S15	RWD	1.9L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	GMC	S15	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	GMC	S15	RWD	2.0L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	GMC	S15	4WD	2.8L	V6	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	GMC	S15	4WD	1.9L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	GMC	S15	RWD	2.2L	L4	122.9"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	GMC	S15	4WD	2.0L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	GMC	S15	RWD	2.2L	L4	108.4"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1984	GMC	S15	RWD	2.2L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	Chevrolet	S10	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	Chevrolet	S10	RWD	2.0L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	Chevrolet	S10	RWD	1.9L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	Chevrolet	S10	4WD	1.9L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	Chevrolet	S10	4WD	2.0L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	Chevrolet	S10	4WD	2.8L	V6	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	GMC	S15	RWD	1.9L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	GMC	S15	RWD	2.8L	V6	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	GMC	S15	RWD	2.0L	L4	—	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	GMC	S15	4WD	2.8L	V6	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	GMC	S15	4WD	1.9L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1983	GMC	S15	4WD	2.0L	L4	118.0"	N/A	If welded assembly, replace all required parts; SoundFX Direct Fit
1982	Chevrolet	S10	—	2.8L	V6	108.4"	N/A	SoundFX Direct Fit
1982	Chevrolet	S10	—	1.9L	L4	118.0"	N/A	SoundFX Direct Fit
1982	Chevrolet	S10	—	1.9L	L4	108.4"	N/A	SoundFX Direct Fit
1982	Chevrolet	S10	—	2.8L	V6	118.0"	N/A	SoundFX Direct Fit
1982	GMC	S15	—	1.9L	L4	108.4"	N/A	SoundFX Direct Fit
1982	GMC	S15	—	1.9L	L4	118.0"	N/A	SoundFX Direct Fit
1982	GMC	S15	—	2.8L	V6	118.0"	N/A	SoundFX Direct Fit
1982	GMC	S15	—	2.8L	V6	108.4"	N/A	SoundFX Direct Fit
No rows match your filter.

Directly replaces or cross-references 2 part numbers

Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.

AMS Automotive — 6590AP Exhaust — 700020