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Flowmaster Catted H-Pipe (99-04 GT)

Market Price $749.60 You Save 12% ($86.24)

$663.36

FREE Shipping
  • Item 18465
  • MPN# 2020027

In Stock Ships same business day. Choose options to add to cart

Features & Details

  • Improves Exhaust Flow and Sound
  • Classic Muscle Car Rumble
  • 2-1/4" Mandrel-Bent Stainless Steel Tubing
  • High Flow Catalytic Converters Included
  • 49 State Emissions Legal
  • For Use with Stock Manifolds or Shorty Aftermarket Headers
  • Fits 1999-2004 GT and Bullitt Mustangs
Improves Flow For More Power. Improve the horsepower and torque of your 4.6L GT Mustang by replacing those restrictive stock cats with a brand new Flowmaster H-Pipe that features high-flow catalytic converters. The Flowmaster high flow catted H-Pipe will significantly improve your Mustang's exhaust flow for a notable increase in horsepower and torque.

Muscle Car Rumble. This free flowing Flowmaster Mid Pipe will not only improve performance, but it will also add a deep muscle car rumble to the sound of your exhaust with its classic "H" crossover pipe design.

Quality Construction. Constructed in the USA from durable 2.25" 16 gauge 409 stainless steel tubing for it's corrosion resistant properties this Flowmaster H-Pipe features four high flow catalytic converters, two main cats and two pre-cats. The included catalytic converters feature a durable ceramic substrate material making them perfect for naturally aspirated applications.

49 State Legal. The included catalytic converters meet or exceed USEPA standards and are 49 state emissions legal. They are not legal for use in the state of California.

Application. This Flowmaster High Performance Catted H-Pipe is designed to be a direct bolt-on replacement for the 1999-2004 4.6L V8 Mustangs, including the GT and Bullitt models with either aftermarket shorty headers or the stock manifolds installed.

Technical note: 2004 Mustangs require the use of 24" O2 sensor plug-in extender wires.

Fitment: 1999 2000 2001 2002 2003 2004 Details

What's in the Box
  • (1) Catted H-pipe
  • (2) clamps
Installation Info
Tech Specs
Mid Pipe Specifications
Style Mid Pipe: Standard length "H" Type Headers Required: Shorty or stock manifolds
Piping Material: Stainless Steel Piping Size: 2.25"
Catalytic Converter: "Yes" Fitment: 1999-2004 GT & Bullitt Mustangs
Will it fit my Mustang?
  • Bullitt - 01
  • GT - 99, 00, 01, 02, 03, 04

Most Helpful Reviews

5/5
GREAT

Adds a little bit and made a better sound over stock highly recommend it!!

Helpful (1)

5/5
Flowmaster Catted H-Pipe

Passed Colorado emissions. Good sound with Bassani Cat Back exhaust. No drone. Fitment with Bassani cat back required some cutting & welding to line up the rear exhaust tips. Very pleased with performance ...

Read More
Helpful (1)

Overall Rating 5 out of 5 stars
Read All 2 Reviews

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2 Questions / 2 Answers

Ask a Question

Would I install this together with the flowmaster catback exhaust system you have on your site as well?

SOUTHBOY

  • You can certainly pair up this Flowmaster Catted H-Pipe (99-04 GT) with the Flowmaster cat back exhaust.

    SalC7

    Good Answer (0) (0)

Question Resolved

HP gain? How much horsepower does this exhaust add?

Darron757

  • The Flowmaster Catted H-Pipe (99-04 GT) will not really increase the power at all. You will get some performance however nothing you will be able to feel. You will though have better exhaust flow from the factory mid-pipe.

    Ricky36

    Good Answer (0) (0)

Question Resolved

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Customer Reviews (2) Write a Review

Overall Rating 5.0

out of 5 stars

Installation Time:Shop Install

Installation Cost:$100-$250

  • Loudness / Volume 5 5
  • Exhaust Note 5 5
  • Fit & Finish 5 5
  • Bang For Your Buck 5 5



  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    May 23, 2013

    Flowmaster Catted H-Pipe

    Passed Colorado emissions. Good sound with Bassani Cat Back exhaust. No drone. Fitment with Bassani cat back required some cutting & welding to line up the rear exhaust tips. Very pleased with performance & quality.

    CRstang99

    Year: 1999 Submodel: GT Denver, CO, USA

    Helpful (1) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    April 02, 2013

    GREAT

    Adds a little bit and made a better sound over stock highly recommend it!!

    JoshE

    Year: 2003 Submodel: GT

    Helpful (1) (0)

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