Exhaust› Exhaust Pipes, Systems and Components

Billy Boat Exhaust

Cat-Back Exhaust System 2-1/2 Inch

$1,231.14

SKU: FPIM-0503

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Billy Boat Exhaust FPIM-0503 is a cat-back exhaust system designed for the 2005-2008 Audi A4 Quattro 2.0T manual transmission. Manufactured from T304 stainless steel, it features a 2-1/2 inch system diameter and twin 3.5 inch double wall tips. This after-cat design is 50-state emissions legal and comes with a limited lifetime warranty.
Show original supplier description
The Billy Boat Exhaust FPIM-0503 cat-back exhaust system is engineered to enhance the performance and sound of the 2005-2008 Audi A4 Quattro with a 2.0T manual transmission. This system replaces the restrictive factory exhaust with a fully polished, mandrel-bent T304 stainless steel tubing set, featuring a 2-1/2 inch diameter for optimal flow. The system incorporates hand-fabricated mufflers utilizing Billy Boat's unique Purge Resonance Technology (PRT) to produce a distinct, pleasing exhaust note that is louder than stock without causing interior resonance. For those seeking a more aggressive tone, an optional sport version replaces the center resonator with a hand-fabricated x-pipe. Visually, the exhaust is finished with twin 3.5-inch round, double-wall polished tips, adding a touch of enthusiast-oriented style. As an after-cat design, this system is 50-state emissions legal. It is backed by Billy Boat's limited lifetime warranty, ensuring long-term durability and customer satisfaction. Key benefits include guaranteed HP and TQ gains, increased fuel mileage, no interior resonance, and an incredibly deep rumble.

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

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandBilly Boat Exhaust
Part NumberFPIM-0503
CategoryExhaust
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

Buy with Confidence

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.

View Full Return Policy

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.

View Full Shipping Policy