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The WALKER 21558 Quiet-Flow® SS Exhaust Muffler is a premium, direct-fit replacement engineered to deliver OE-style sound, long-lasting durability, and reliable exhaust performance for select Chevrolet Impala and Monte Carlo models. As the only broad-market muffler constructed with 100% stainless steel, the Quiet-Flow SS series offers superior corrosion resistance and dramatically longer life than aluminized alternatives.
Internal partitions and mechanically joined tubes allow the muffler to expand and contract with temperature changes while retaining structural integrity. OE-style louvered tubes and domed heads improve acoustic tuning and reduce radiated noise, delivering smooth, factory-correct sound quality. The integrated internal drainage system helps remove moisture, further reducing corrosion.
Designed for effortless installation, the WALKER 21558 features OE-style hangers, brackets, and pipe routing, making it a true bolt-on solution without welding or custom fabrication. Every Quiet-Flow SS muffler is acoustic and flow tested to ensure dependable performance and precise fitment.
100% Stainless-Steel Construction for maximum rust resistance and extended life
Direct-Fit Bolt-On Installation with OE-style hangers and brackets
Durable Internal Structure allows thermal expansion without distortion
Premium Sound Control using OE-style louvered tubes and domed heads
Internal Drainage System reduces moisture accumulation
Flow & Acoustic Validated for OE-quality performance
Backed by Walker’s Limited Lifetime Warranty and 90-Day Safe & Sound® Guarantee
| Specification | Detail |
|---|---|
| Shape | Oval |
| Finish | Aluminized |
| Body Material | Stainless Steel |
| Inlet Type | Pipe Connection |
| Outlet Type | Tip |
| Inlet Inside Diameter | 2.250 in |
| Outlet Outside Diameter | 2.250 in |
| Inlet Location | Offset |
| Inlet Quantity | 1 |
| Outlet Location | Center |
| Outlet Quantity | 1 |
| Body Height | 5.500 in |
| Body Length | 15.000 in |
| Body Width | 11.000 in |
| Overall Length | 27.125 in |
| Inlet Offset | 3.750 in |
| Hanger Included | Yes |
| Reversible | No |
| Tunable | No |
| Universal or Specific Fit | Specific |
| Grade Type | Premium |
(Direct-fit applications. One muffler required per vehicle.)
3.5L V6 (3490cc / 213 cid)
2006–2011
3.5L V6 (3490cc / 213 cid)
2006–2007
Designed for direct bolt-on replacement—no welding required
Inspect clamps, hangers, and gaskets before installation
Ensure proper inlet/outlet orientation—muffler is not reversible
Quiet-Flow® SS mufflers are backed by a Limited Lifetime Warranty
Includes 90-Day Safe & Sound® Guarantee from Walker
Order Processing
All orders are processed and shipped within 24 hours of purchase (excluding weekends and holidays).
Orders placed after 3:00 PM EST may ship the following business day.
Shipping Methods
Customers select their preferred shipping method and speed at checkout.
Shipping times are determined by the carrier and cannot be guaranteed by us.
Tracking information will be provided once your order has shipped.
Shipping Coverage
If your package arrives damaged, please notify the delivery driver immediately and contact the shipping carrier to file a claim.
You must report any missing or damaged items within 14 days of delivery.
After this time, we cannot be held responsible for lost or damaged items.
Return Window
You have 30 days from the date of delivery to request a return.
After 30 days, we are unable to accept returns, exchanges, or refund requests.
Eligibility
Items must be returned in their original condition—unused, unwashed, and with all tags and packaging intact.
Certain products may not be eligible for return (e.g., special-order items, customized products, or perishable goods).
Items that have been altered, installed, or modified cannot be returned.
Return Process
Contact our Customer Support team to request a Return Authorization (RMA) before sending items back.
Once your return is approved, you’ll receive instructions on where to send the product.
Customers are responsible for return shipping costs unless the item was defective or incorrect.
Refunds
Refunds are issued to the original payment method once the returned item has been received and inspected.
Please allow 5–10 business days for the refund to appear on your account.
In some cases, a restocking fee may apply (if applicable, this will be disclosed during your return authorization).
