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Exhaust› Mufflers and Resonators

Flowmaster

40 Series Chambered Muffler 40 Series 2.50 Offset In 2.50 Offset Out Aggressive Sound Flowmaster

$114.95 $101.95 Save $13.00

SKU: F00L 42543

In Stock
In Stock
Ships by Oct 22
Free Shipping over $200
$100 Minimum Order
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Flowmaster 40 Series muffler is designed to deliver a bold, aggressive exhaust sound, making it a popular choice for enthusiasts. Featuring a classic two-chambered internal design, it produces the signature Flowmaster bark and tone known for its street presence. Constructed from 16-gauge aluminized steel and fully MIG-welded, this muffler is built to withstand high heat and vibration without internal packing that could wear out. Its universal fitment is intended for custom and modified exhaust systems, offering simplified installation and optimal fitment with multiple inlet/outlet sizes and configurations.
Show original supplier description

Part #: 42543

The Original 40 series muffler delivers an aggressive exterior and interior tone. If you're looking for that original Flowmaster sound this is the muffler is for you.Constructed of 16 gauge aluminized steel and fully MIG welded for maximum durability.Durable fully welded 16 gauge aluminized steelAggressive Sound Exterior Exhaust ToneNoticeable interior resonanceExcellent Street/Strip and Off Road application

Features:

  • Durable Fully Welded 16ga Aluminized Steel
  • Durable fully welded 16 gauge aluminized steel
  • 3 Year Limited Warranty
  • Aggressive Sound Exterior Exhaust Tone
  • Aggressive And Powerful Exterior Exhaust Tone
  • Noticeable interior resonance
  • Notable Interior Resonance
  • Excellent Street/Strip and Off Road application
  • No Internal Packing To Blowout
  • The Original Two Chamber Design
  • Premium Flowmaster Quality
  • Excellent Street/Strip And Off Road Application

40 Series (TM) Muffler | 2.5 in. Offset Inlet/Outlet | Case Dimensions 4 in. x 9.75 in. x 13 in. | 19 in. Overall Length | Aluminized Steel

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandFlowmaster
Part NumberF00L 42543
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1M+ Enthusiasts
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(760) 282-4645 hello@motormia.co

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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