Flowmaster
Flowmaster 40 Series Muffler - 2.50 IN(D)/OUT(D) - Aggressive Sound
* Images may be a representation and may not reflect the actual product.
Product Details
The Original 40 series muffler delivers an aggressive exterior and interior tone. If youre looking for that original Flowmaster sound, this is the muffler for you. Constructed of 16 gauge aluminized steel and fully MIG welded for maximum durability.
SPECS
40 Series Muffler - 2.50 IN(D)/OUT(D) - Aggressive Sound
Universal 40 Series Muffler - 2.50 IN(D)/OUT(D) - Aggressive Sound
Muffler - Original 40 Series - Dual 2.5 in Inlets - Dual 2.5 in Outlets - 13 x 9.5 x 4 in Oval Body - 19 in Long - Steel - Black Paint - Universal - Each
SPECS
- Engine Liter:
- CC:
- CID:
- Quantity:
40 Series Muffler - 2.50 IN(D)/OUT(D) - Aggressive Sound
Vehicle Fitment
Universal or product-specific fitment. Please review the product details and contact us if you need help confirming fitment before ordering.
Product Specs
- Brand
- Flowmaster
- Part Number
- 425404
- Catalog Number
- 001068103
- Product Line
- 40 Series
- Category
- Exhaust
- Type
- Muffler
- UPC / Barcode
- 700042026029
- Length
- 20.50 in
- Width
- 10.00 in
- Height
- 5.00 in
- Weight
- 10.32 lb
- Freight / LTL
- 175.00
- Ship Alone
- No
- Air Restricted
- No
- Hazmat
- No
- Chemical
- No
- Non-Returnable
- No
- Case Quantity
- 1
- Kit
- No
Shipping & Availability
This item is showing available inventory. Most in-stock performance parts ship quickly, but timing can vary by warehouse, vendor cut-off time, holidays, and carrier pickup.
Inventory shown: 84 available as of 6/4/2026.
FLOWMASTER CLAIMS POLICY: All claims for wrong item received, damages and/or shortages MUST be made within 10 days after receipt of shipment. Please be sure to inspect your order upon receiving it and let us know right away if there are any issues. PLEASE NOTE: Most manufacturers will not issue a Return merchandise authorization for claims of this nature if the claim is not made within the above stated time frame.
Lifetime Limited Warranty applies to Flowmaster stainless steel mufflers (excluding FlowFX series), all stainless steel exhaust systems (including FlowFX series), stainless steel pipes, air intake kits and oiled type filters (except cleaning kits), and other stainless steel exhaust accessories (except exhaust tips and racing products).
Three (3) Year Limited Warranty applies to Flowmaster aluminized steel mufflers, aluminized steel exhaust systems, aluminized steel pipes, exhaust tips and other non-race exhaust accessories.
Two (2) Year Limited Warranty applies to Delta Force Dry air intake filter elements.
One (1) Year Limited Warranty applies to FlowFX series mufflers, Elite Series exhaust headers and electronic components such as Delta Boost modules.
Flowmaster, Inc. (“Flowmaster”) extends the following limited warranty to the original purchaser of its mufflers, exhaust systems, pipes, exhaust tips, headers and other non-race accessories (hereafter “products”), excluding catalytic converters sold under the Flowmaster brand. Flowmaster warrants the products mentioned above against defects in materials and workmanship for the period set forth below, when they are owned by the original purchaser and remain installed on the vehicle on which they were originally installed. This warranty is void if the product was not installed properly on the vehicle, was installed on a vehicle for which it was not designed, or was removed from the vehicle on which it was originally installed and reinstalled on another vehicle. This warranty shall not apply to normal wear, including interior/exterior sound levels, cosmetic issues such as coatings and material discoloration, any product that was installed on a racing vehicle, installed improperly or contrary to Flowmaster instructions, altered, misused, repaired, damaged from an accident, collision, undercarriage road impact or debris, or willful or negligent act. Note that all “straight-through” mufflers which use sound absorbing material inside the muffler to cancel sound…will degrade over time. This degradation of sound absorbing materials is considered “normal wear”…not a material defect.
The warranty set forth herein for Flowmaster stainless steel mufflers (except FlowFX), all stainless steel exhaust systems, stainless steel pipes, stainless steel exhaust accessories (except exhaust tips) and air intake kits and oiled type filters (except cleaning kits), extends for a period of the life of the original vehicle the product was installed on. The warranty set forth herein for Flowmaster aluminized steel mufflers, aluminized steel exhaust systems, aluminized steel pipes, all exhaust tips and non-race exhaust accessories and commercial applications of aluminized steel products or stainless steel products extends for a period of three (3) years from the date of original purchase and the original vehicle it was installed on. The warranty set forth herein for Flowmaster dry air intake filter elements extends for a period of two (2) years from the date of original purchase and the original vehicle it was installed on. The warranty set forth herein for Flowmaster Exhaust headers, FlowFX mufflers, and Delta Boost modules extends for a period of one (1) year from the date of original purchase and the original vehicle it was installed on. Header warranty does not cover damages caused by exhaust insulating wrap, and is void if the product was installed on a new or rebuilt engine during the initial break-in period.
Reviews & Questions
Real product feedback when available, plus quick ways to get fitment or product help.
Other Popular Muffler
The performance exhaust is an important part of your performance car. Flowmaster is one of the oldest and most respected and recognized names in aftermarket performance exhausts and one of the reasons LMPerformance carries Flowmaster American Thunder, and Flowmaster 40 Series Exhaust systems. For over thirty years Flowmaster has been one of the leaders in the design of specialty aftermarket exhaust parts. Flowmaster American Thunder & Flowmaster 40 series were first established to design and manufacture exhausts for racing in California. Flowmaster now produces performance exhaust systems, mufflers, and other products for a wide range of cars (including Mustangs, Camaros, Challengers, Corvettes, Chargers), trucks, SUV's, motorhomes and ATV'S. They create a line of high-performance "chambered" mufflers that is well known in the industry.
Flowmaster offers eleven diffferent series of mufflers that give top notch performance and great sound levels and tones. Flowmaster is especially noted for their Flowmaster 40 series muffler, with its original Flowmaster American Thunder sound and tone. If you're in the market for a Flowmaster 17106 Ford Mustang exhaust system- look no further!
Review our return, cancellation, shipping, warranty, and product image policies before ordering.
Contact us with questions before ordering
California Residents: Prop 65 WARNING: This product MAY contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Wash hands after handling. For more information, visit www.P65Warnings.ca.gov
California Residents: TIRE WARNING: LMPerformance will not ship Tires to California.
Legal: Some or all of these parts may not comply with Federal, State, Province, and/or Local laws, ordinances, and regulations. Buyer takes all responsibility to ensure that any modifications or upgrades that have done conform to all applicable laws and regulations for road use, especially pertaining to safety and emissions. LMPerformance is not responsible for buyer not complying with Federal, State, Province, and/or Local laws, ordinances, and regulations. This policy shall be in force for all past, current, and future purchases from LMPerformance, Inc. LMPerformance will not ship ANY non-CARB compliant products to California where California requires products to be CARB certified such as Catalytic Converters and Induction Kits.
Free Shipping: Please note FREE Shipping refers to shipping within the contiguous continental US only. All other locations extra. Some items that require Truck Freight Delivery will require a Truck Freight surcharge. This surcharge is still a discounted shipping amount that is lower then the actual truck freight shipping charge that is charged to LMP. LMP will try to still give the lowest price possible for truck freight items.
Images: Images may be a representation and may not reflect the actual product. Examples would be SPEC stage 3 clutch kits which all use the same photo.
TYPOS: LMPerformance tries to present the best most accurate information on our website. Sometimes we get mistakes in product information sent from vendors such as typos. We can not be responsible for these typos, if you see something that does not look right please let us know before ordering so we can double check for you first. LMPerformance will not pay for typos in any way, monetarily or otherwise.
Price Errors: In the event that a product has mistakenly been listed at an incorrect price, We reserve the right to refuse or cancel any orders placed for product listed at the incorrect price. We reserve the right to refuse or cancel any such orders whether or not the order has been confirmed and your account charged. If your payment type has already been charged for the purchase and your order is cancelled, a full refund to your orignial payment method in the amount of the incorrect price will be issued.
Special Order ITEMS: Some items are Special Ordered and may not be returnable, or even cancellable as they are going into production specifically because you ordered them. Special Ordered items can have a 5-35% cancelation fee.
Cancellations: Instock orders cannot be canceled due to our automated ordering & fast shipping system. To keep our prices low, all cancelations are subject to a 5% cancelation fee to cover transaction processing fees. We reserve the right to charge up to a 10% cancellation fee for cancelled orders due to merchant fees, Special Order fees and the cost of processing and shipping orders.When you request a cancellation of an order or a part, please note that it may take time for a manufacturer to cancel an order if the order is drop-shipped. We also have to confirm that the product has not shipped. If the product has shipped then this must be processed as a return.Also note that sometimes products ship more quickly than expected, so we recommend that you do not purchase alternative products until receiving final confirmation of the cancellation.
Returns: We cannot accept returns on parts that have been used or installed. No returns will be accepted after 30 days. All Returns must be in original packaging. Prior authorization must be given before any return can be made. Up to a 25% Restocking Fee may apply. Special Orders may be subject to Additional Manufacturer Restock Fees as well. Shipping cost will not be refunded.Hoods as well as PCM Programmers may not be returned unless defective and only for replacement. ALL returns must be first filed using our online form found here: https://www.lmperformance.com/returns.
Lost Order Claims All lost order/package claims must be made within 5 days of the shipping date or tracking information delivery date. All claimes made after this date will not be accepted due to Shipping companies policies of filing loss claims.
Damaged Items or Incorrect Items: Please contact us right away if your item has been damaged in shipping or are incorrect. Please note that we will ship replacement items the same method of shipping the order was originally placed for. LMPerformance can not ship packages overnight at our cost if the original shipping was not also overnight. Claims must be filed in order for replacement parts to be shipped.
Warranties:Any warranty claims must be placed with the manufacturer. All of the products sold by LMPerformance, regardless of the manufacturer, are designed for Racing and Performance applications. Many of our manufacturers offer NO WARRANTY on their products, either stated or implied, due to the unusual stresses placed on the parts and because we have no control over how they are installed and used. Many of these products are designed for off-road use only and are not legal for use on public highways. If you have a question about the warranty on a specific product, please e-mail or call us. Buyer assumes all risk and liability associated with these products.
Installation: We are not responsible for or any costs associated with the installation or the improper installation of any products. Purchaser assumes the risk associated with the installation of products. We, along with the manufacturer of each product are not responsible for any direct or indirect damage to the vehicle, personal, or costs incurred from the use of products.