Flowmaster Mustang High-Performance Catted Y-Pipe 2020023 (99-04 V6)

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

19 Reviews 11 Answers

Market Price $687.47 You Save 12% ($79.09)

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$608.38

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Item 18464
MPN# 2020023

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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

Product Resources

Customer Photos (2) Customer Reviews (19) Questions (11) & Answers (11)

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

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

What's in the Box

(1) Catted Y-pipe
(2) clamps

Installation Info

Installation Time: (approx) 2 Hours

Difficulty Level:Light to Moderate mechanical skill required.

Installation Guides:

Customer Submitted:
How to Install Flowmaster High-Performance Catted Y-Pipe on your Ford Mustang

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

Tech Guides:

Fox Body Catalytic Converters - Aftermarket Fundamentals

Will it fit my Mustang?

V6 - 99, 00, 01, 02, 03, 04

Questions & Answers (11)

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)

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)

I have glass pack dual exhaust system would that work wt my 2002 v6 3.8 mustang ?

As long as the dual exhaust system has a connection for the Y-pipe then yes, it will work.

Helpful (0)

Not finding an answer? Ask your question! Post Your Question

6 More Questions

Will this work with bbk shoe is ceramic headers? 1 answer

As long as they are shorty headers, these will fit no problem.

Helpful (0)

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

The Flowmaster High-Performance Catted Y-Pipe (99-04 V6) will work with the Flowmaster Force II Dual Cat-Back Exhaust (99-04 V6), item # 18420, (http://www.americanmuscle.com/flowmaster-force2-catback-9904v6.html).

Helpful (0)

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

Hi, This Flowmaster High-Performance Catted Y-Pipe can be used with the PaceSetter V6 Dual Exhaust Adapter Kit you will have to cut off the Y-pipe and clamp the adapter in its place, I suggest having a shop do that because its must be perfectly cut.

Helpful (0)

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

The Flowmaster High-Performance Catted Y-Pipe (99-04 V6) feature a 2.25" stainless steel tubing while the MAC Dual Exhaust Conversion Kit (99-04 V6), item # 40048, (http://www.americanmuscle.com/99-04-v6-mac-catback.html) features a 2.5" aluminized steel tubing. Since they are two different sizes, they will not directly bolt together. You may need to do some cutting and welding to have a proper install. We recommend professional installation of both these items.

Helpful (0)

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

In an H-pipe, the two exhausts are connected, but the do not merge into one, as they do in a Y-pipe. It appears off-road H-pipes are available for the V6. For on-road (catted) applications, some custom exhaust work may be required.

Helpful (0)

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

Yes, i bought this right after i installed my Magnaflows and they sound awesome.

Helpful (0)

People Who Bought This Item Also Bought

Customer Reviews (19) Write a Review

Overall Rating

4.5

out of 5 stars

Installation Time:Full Day

Installation Cost:$100-$250

Loudness / Volume 3.789474 3.8
Exhaust Note 4.473684 4.5
Fit & Finish 4.31579 4.3
Bang For Your Buck 4.631579 4.6

no one in the world ever gets what they want, and that is beautiful

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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 (3) Thanks for your input!
- Loudness (Volume) 3
  3
- Exhaust Note 5
  5
- Fit & Finish 5
  5
- Bang for your Buck 5
  5
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 (3) Thanks for your input!
- Loudness (Volume) 4
  4
- Exhaust Note 5
  5
- Fit & Finish 5
  5
- Bang for your Buck 5
  5
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 (3) Thanks for your input!
- Loudness (Volume) 4
  4
- Exhaust Note 5
  5
- Fit & Finish 5
  5
- Bang for your Buck 5
  5
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 (3) Thanks for your input!
- Loudness (Volume) 4
  4
- Exhaust Note 4
  4
- Fit & Finish 4
  4
- Bang for your Buck 4
  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 (3) Thanks for your input!
- Loudness (Volume) 3
  3
- Exhaust Note 4
  4
- Fit & Finish 4
  4
- Bang for your Buck 5
  5
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 (3) Thanks for your input!
- Loudness (Volume) 5
  5
- Exhaust Note 5
  5
- Fit & Finish 5
  5
- Bang for your Buck 5
  5
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 (4) Thanks for your input!
- Loudness (Volume) 3
  3
- Exhaust Note 5
  5
- Fit & Finish 5
  5
- Bang for your Buck 5
  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 (6) Thanks for your input!
- Loudness (Volume) 3
  3
- Exhaust Note 3
  3
- Fit & Finish 4
  4
- Bang for your Buck 4
  4
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 (6) Thanks for your input!
- Loudness (Volume) 3
  3
- Exhaust Note 4
  4
- Fit & Finish 5
  5
- Bang for your Buck 5
  5
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 (8) Thanks for your input!
- Loudness (Volume) 3
  3
- Exhaust Note 4
  4
- Fit & Finish 5
  5
- Bang for your Buck 4
  4
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 (6) Thanks for your input!
- Loudness (Volume) 5
  5
- Exhaust Note 5
  5
- Fit & Finish 4
  4
- Bang for your Buck 5
  5
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 (4) Thanks for your input!
- Loudness (Volume) 5
  5
- Exhaust Note 5
  5
- Fit & Finish 5
  5
- Bang for your Buck 5
  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 (5) Thanks for your input!
- Loudness (Volume) 4
  4
- Exhaust Note 5
  5
- Fit & Finish 3
  3
- Bang for your Buck 3
  3
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 (4) Thanks for your input!
- Loudness (Volume) 2
  2
- Exhaust Note 3
  3
- Fit & Finish 5
  5
- Bang for your Buck 5
  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 (5) Thanks for your input!
- Loudness (Volume) 5
  5
- Exhaust Note 5
  5
- Fit & Finish 5
  5
- Bang for your Buck 5
  5
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 (4) Thanks for your input!
- Loudness (Volume) 4
  4
- Exhaust Note 4
  4
- Fit & Finish 2
  2
- Bang for your Buck 5
  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 (5) Thanks for your input!
- Loudness (Volume) 5
  5
- Exhaust Note 5
  5
- Fit & Finish 4
  4
- Bang for your Buck 4
  4
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 (7) Thanks for your input!
- Loudness (Volume) 4
  4
- Exhaust Note 5
  5
- Fit & Finish 3
  3
- Bang for your Buck 4
  4
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 (10) Thanks for your input!
- Loudness (Volume) 3
  3
- Exhaust Note 4
  4
- Fit & Finish 4
  4
- Bang for your Buck 5
  5

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

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$608.38

+$453.95

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+$399.99