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Flowmaster High-Performance Catted Y-Pipe (99-04 V6)

AmericanMuscle no longer carries the Flowmaster High-Performance Catted Y-Pipe (99-04 V6). Please check out 1999-2004 Mustang H-Pipes for an updated selection.

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 V6 Mustangs
Regain Lost Power. Replace those clogged or blown-out stock catalytic converters with high performance Flowmaster replacements to regain lost 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 "Y" 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 Y-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 Y-Pipe is designed to be a direct bolt-on replacement for the 1999-2004 3.8L or 3.9L V6 Mustangs with either aftermarket shorty headers or the stock manifolds installed.

Fitment: 1999 2000 2001 2002 2003 2004 Details

MPN# 2020023

CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

What's in the Box
  • (1) Catted Y-pipe
  • (2) clamps
Installation Info
Tech Specs
Mid Pipe Specifications
Style Mid Pipe: "Y" Type Headers Required: Shorty or stock manifolds
Piping Material: Stainless Steel Piping Size: 2.25"
Catalytic Converter: "Yes" Fitment: 1999-2004 V6 Mustangs
Will it fit my Mustang?

    Customer Photos (2) Submit Your Photo

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      Questions & Answers (12)

      5 Top Rated Questions

      How much horsepower will this add? What is the difference between this and the Pypes catted X-pipe

      • The amount of HP that you will add with this bolt-on depends on what mods you already have done to the car. A y-pipe is a 2-into-1 pipe that is made for the stock single exit exhaust. An x-pipe is made for true dual exhaust and will flow much more than a 'y'.

      Helpful (1)

      Can you use an H pipe with this??

      • The Flowmaster High-Performance Catted Y-Pipe can be paired with stock and aftermarket mid-pipes including H-pipes.

      Helpful (0)

      Would this work with the mac dual exhaust conversion kit 99-04 mustang?

      • The Flowmaster High-Performance Catted Y-Pipe is compatible with the MAC Dual Exhaust Conversion Kit.

      Helpful (0)

      If I delete the two catts in the rear would my check engine light come on..

      • The Flowmaster High-Performance Catted Y-Pipe is designed to work with all of the cats in the Y pipe installed. Deleting these has not been tested, but is expected to cause the check engine light to come on for catalyst efficiency.

      Helpful (0)

      I have the flow master dual cat backs already installed. I have clogged cats now and would like to replace them with this catted y-pipe. Will it fit in with the flow masters i already have?

      • Hello! Yes this will work in conjunction with your Flowmaster catback!

      Helpful (0)
      Post Your Question
      7 More Questions
      I have glass pack dual exhaust system would that work wt my 2002 v6 3.8 mustang ? 1 answer
      Will this work with bbk shoe is ceramic headers? 1 answer
      Silly question but I feel the need to ask.... Will this hook up to a Flowmaster force 2 duel exhaust cat back system already installed? Thanks 1 answer
      Would this exhaust work with the v6 dual exhaust adapter kit by pacesetter? As in i want to buy a GT catback to have dual exhaust from the headers to the tips. 1 answer
      I have the Mac dual conversion exhaust kit for my 2000 v6,would this bolt right up to it or would the piping be different? 1 answer
      This or H pipe for MAC Dual Exhaust conversion kit? I currently have the MAC Dual Exhaust Conversion Kit on my 2003 mustang v6 and wanted to do more to get that classic growl/rumble. Would it be possible to get an H pipe that will connect to this or would it be better to just get the Flowmaster high performance catted Y pipe? 1 answer
      Fitting Issues I already have a Magnaflow Dual Exhaust for my 04 V6. Just wondering would this product fit well with my exhaust 1 answer

        Customer Reviews (20) Write a Review

        Overall Rating 4.6

        out of 5 stars

        Installation Time:Full Day

        Installation Cost:$100-$250

        • Loudness / Volume 3.75 3.8
        • Exhaust Note 4.4 4.4
        • Fit & Finish 4.3 4.3
        • Bang For Your Buck 4.6 4.6



        • 5/5

          Installation Time: Afternoon

          February 01, 2019

          Best deal ever

          My stock ones for some reason broke before the manifold, but now is the new

          Ches

          Year: 2003 Submodel: V6

          Helpful (1)

        • 5/5

          Installation Time: Less than 1 Hour

          May 17, 2018

          Awesome

          Was an easy install went together fairly quickly, took about 30 minutes, and an extra pair of hands

          Karmastang89

          Year: 2004 Submodel: V6

          Helpful (4)

        • 5/5

          Installation Time: Afternoon

          January 18, 2018

          Excellent product

          Easy to install and great product. Took me a little longer to install due to having big hangs and getting to o2 sensors to unlatch and replug.

          BigCountry

          Year: 2003 Submodel: V6

          Helpful (4)

        • 5/5

          Installation Time: Less than 1 Hour

          November 19, 2017

          Flowmaster high performance catted y-pipe

          I love the way new flowmaster exhaust system on my 2001 mustang and the way it makes my car sounds. And perform. Thanks American Muscle

          FredO

          Year: 2000 Submodel: V6

          Helpful (4)

        • 3/5

          Installation Time: Shop Install

          Installation Cost: $500-$1000

          November 06, 2017

          2004 V6

          Welp I love the way this sounds when paired to my Dual MAC exhaust ... but after one year of own it has changed color , looks a lil rusty, anddd the heat shields fail leaving me w a terribly loud and dealthy sounding rattle . Easy fix is to clamp it with some of those big circle pipe clamp things . Not a big deal to me but all of this is worth mentioning

          DolenR

          Year: 2004 Submodel: V6

          Helpful (4)

        • 4/5

          Installation Time: Weekend

          September 22, 2017

          Great Part!

          The y-pipe has an awesome sound and the car drives better than it ever has!

          DuaneI

          Year: 2000 Submodel: V6

          Helpful (4)

        • 5/5

          Installation Time: Shop Install

          Installation Cost: $100-$250

          July 08, 2017

          2000 mustang

          Great product we had our mechanic install this for us!!!!!

          Tjev

          Year: 2000 Submodel: V6

          Helpful (4)

        • 3/5

          Installation Time: Afternoon

          April 14, 2017

          HOOKER EXHAUST Y PIPE WITH CATALYST

          PRODUCT IS GREAT and THE OPERATOR WHO HANDLED THE CALL WAS GREAT, EXHAUST CLAMP WAS MISSING FROM BOX, AND THE BUNG PLUGS WHERE NOT TIGHT. LOST PLUG,

          AlbertF

          Year: 2003 Submodel: V6

          Helpful (5)

        • 5/5

          Installation Time: Afternoon

          March 18, 2017

          Great product

          I bought this because my mid pipe broke so i figured i might as well upgrade. Install was pretty easy, i comes in three different pieces so it was manageable with two people. Didn't really have to force anything too much. I did notice a much smoother drive than before which i was very pleased with this Y pipe.

          RonnieH

          Year: 2004 Submodel: V6

          Helpful (7)

        • 5/5

          Installation Time: Less than 1 Hour

          February 24, 2017

          So much smoother!

          Got the y pipe really fast! The welds were amazing and it looked so clean. A shop was charging me $1,800 for a catted y pipe so at this price you definitely can't beat it. I was worried it wasn't gonna fit but took it to a shop and got charged $100 and it fit perfectly!! The noise isn't loud. It does give it a deeper tone but not loud at all. It made my car run so much smoother and actually it got a bit faster. It regained all its lost power and it runs and sounds amazing!!! Thanks american muscle!!

          AlexisC

          Year: 2002 Submodel: V6

          Helpful (7)

        • 4/5

          Installation Time: Shop Install

          Installation Cost: $100-$250

          December 28, 2016

          Excellent for Performance!

          I got my entire exhaust system from American Muscle and went from sound to performance. It runs incredibly now. (2004 40th Anniversary mustang)

          Kac

          Year: 2004 Submodel: V6

          Helpful (9)

        • 5/5

          Installation Time: Afternoon

          September 18, 2016

          Awesome sound

          I brought this because my catalytic covertes were wrong and I need to past the inspection but this was the best decision, sound is perfect and add a little bit of hp to the car, I have mad dual exhaust and this is the perfect combination, looking forward to but some headers Thanks American mucke

          Mike

          Year: 2000 Submodel: V6

          Helpful (7)

        • 5/5

          Installation Time: Afternoon

          July 02, 2016

          Very happy!

          Now we want to get the rest, when the price is right. It is well built. Thank you, Sally

          mustangsally

          Year: 2000 Submodel: V6

          Helpful (5)

        • 4/5

          Installation Time: Afternoon

          November 14, 2015

          Catrick Y-Pipe

          The product looks awesome. Before you put it on, you can tell your V6 will turn into a beast! I can tell the performance has changed already! Looking forward to getting better mileage and more stares at my awesome ride!

          MissRight25

          Submodel: V6 Las Vegas, NV

          Helpful (6)

        • 5/5

          Installation Time: Shop Install

          September 24, 2015

          2003 v6 clogged cats

          $160 shop install. 2.5 hours. More hp, better mpg, high quality. V6 so not loud. Free flowing. Good welds.

          Marcus478

          Year: 2003 Submodel: V6 Americus Ga

          Helpful (5)

        • 5/5

          Installation Time: Shop Install

          Installation Cost: $100-$250

          June 14, 2015

          Coo Catt

          Product arrived exceptionally quick! Took it to the shop for the install. I didn't make any other modifications so the sound is reminiscent of the stock not loud at all. I wasn't looking for sound so everything is good so far!

          Vegas

          Year: 2004 Submodel: V6 Lake Charles

          Helpful (6)

        • 4/5

          Installation Time: Afternoon

          April 29, 2014

          Not a typical DIY

          The fitment of the left side was off. I removed and installed in about 1 1/2 hrs but had an exhaust leak at the connection to the shorty header. I had to cut off the pipe just in front of the first CAT then cut a wedge off the pipe rotate about 15-20 degrees and weld it back to the CAT. After the modification it worked beautifully.

          HALOJM

          Year: 2002 Submodel: V6 Vernal, UT

          Helpful (5)

        • 5/5

          Installation Time: Shop Install

          Installation Cost: $100-$250

          February 01, 2014

          nice sound

          this with the combo of the duels that I also purchased turned my v6 into a v8 sound. what a difference.

          sunshine

          Year: 2004 Submodel: V6 Hawaii, USA

          Helpful (6)

        • 5/5

          Installation Time: Shop Install

          Installation Cost: $250-$500

          December 20, 2013

          Tricky Satisfaction

          After doing a lot of research and waiting for the right time to get this product on my 03 V6, I have to say the wait and the headache were well worth the wait. I bought this mid pipe about 2 months ago and have been dying to get them on my car with my BBK shorties. After taking it to a DIY shop, I realized this wasn't gonna be a DIY job and decided to take it to a shop and after waiting two days i got my car back with my Shorties and Mid pipe installed and immediately heard and felt a difference. With the BBK Shorties and Magnaflow Dual Exhaust system i bought. The whole package has made me a happy camper. If you are still debating on whether to buy this product, stop debating and order them now. GREAT BUY AND GREAT SOUND. AM has knocked it out of the park like always. Will post a pic shortly

          SGTdavila

          Year: 2003 Submodel: V6 Havelock, NC

          Helpful (8)

        • 4/5

          Installation Time: Afternoon

          April 21, 2013

          happy with this buy

          I am very happy with the price of the product. I started with putting 40 series cat back dual exhaust, but i needed a new driver side cat. I had quoted a shop and they were going to charge me about 1,500 to do it. So i ventured onto american muscle and found the flowmaster catted perfomance y-pipe and couldn't beat the price. So it is flowmaster from the headers back. Next step is the cool air intake!!! Which i will be getting from American muscle.

          babgrl817

          Year: 2001 Submodel: V6 Franklinville, Franklin, NJ, USA

          Helpful (11)

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