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Magnaflow Street Cat-Back Exhaust (99-04 GT, Mach 1)

Market Price $907.68 You Save 32% ($288.80)
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  • Item 48012
  • MPN# 15671

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    Features, Video & Details

    • Classic Muscle Car Sound
    • Street Series Muffler - Straight-Through Design
    • Durable, Stainless Steel Construction
    • 2.5" Mandrel-Bent Tubing
    • 3.5" Polished Stainless Steel Tips
    • Fits 1999-2004 GT, Bullitt and Mach 1 Mustangs

    Review & Installation Video

    Review & Install Video

    Hey I’m Justin with, and this is my quick look into the Magnaflow catback exhaust system fitting the 99-04 Mustang GT and Mach 1. Right off the bat, I can tell you this isn’t going to be the loudest kit in the world, thanks in part to the traditional chambered muffler design. What you can expect from this kit is for it to be slightly more aggressive than stock, when idle and while cruising, but really comes to life when you get on the throttle. Just because this system is a little on the quiet side doesn’t make it a bad exhaust, as a matter of fact it’s far from it. We’re looking at a full stainless steel constructions throughout, including 2.5” mandrel bent tubing, quality welds, and a quality finish, both on those chambered mufflers, and on those 3.5” flared polished tips. As the factory exhaust is all one piece you will need to cut it off with a saw or something similar, once you get that out of the way, getting the magnaflow installed is a very straightforward task, that should take you about 2 hours using standard hand tools. Now let’s hear how Magnaflow’s catback exhaust system sounds compared to your factory exhaust.

    Free Flowing Exhaust. Magnaflow delivers the ultimate exhaust for the 99-04 GT, Bullitt, and Mach 1 Mustangs with this Street Cat-Back Exhaust System. By reducing back pressure for a free flowing exhaust, more power and torque is produced where it belongs - at the rear wheels.

    Classic Muscle Car Sound. The Magnaflow Cat-Back Exhaust System includes a set of two Street Series Mufflers that feature a free-flowing, straight-through perforated stainless steel core, with stainless mesh wrap and acoustical fiber fill to deliver that smooth, deep muscle car tone.

    Quality Construction. Each piece of this Street Exhaust is made from 2.5" mandrel bent stainless steel tubing for long life and a perfect fit. The system is finished off with brightly polished 3.5" stainless steel tips that exit from the stock location for impressive good looks.

    Application. Made to be a direct bolt on, this Magnaflow Street Cat-Back Exhaust will bolt straight up to the factory Mid Pipe without any extra modifications required on 1999-2004 GT, 2001 Bullitt or 2003-2004 Mach 1 Mustangs.

    Note: Coupon codes cannot be applied to this product.

    Lifetime Warranty is included with all Magnaflow catback systems.

    Fitment: 1999 2000 2001 2002 2003 2004 Details

    What's in the Box
    • (2) Flow Tubes
    • (2) Tail Pipes
    • (2) Mufflers
    • (2) Turn-Down Tips
    • (2) Set Screws w/ Allen Wrench
    • (2) Tip Hangers
    • (6) 1.25" x 2.5" Band Clamps
    • (2) Header Mounting Flanges
    Installation Info
    Tech Specs
    Cat-Back Exhaust Specifications
    Piping Material: Stainless Steel Tip Material : Polished Stainless Steel
    Piping Size: 2.5" Tip Size: 3.5"
    Muffler Type: Straight-through Fitment: 1999-2004 GT / Mach 1 / Bullitt
    Will it fit my Mustang?
    • Bullitt - 01
    • GT - 99, 00, 01, 02, 03, 04
    • Mach 1 - 03, 04

    Most Helpful Reviews

    Fits and sounds great

    Put this on my 99 GT. Took a little effort to get it all lined up but it is doable. With stock h-pipe the sound was a little deeper and louder than stock but not much. I then added an off-road x-pipe. ...

    Read More
    Helpful (11)

    Very Nice Exhaust

    This kit is the best. The fit is perfect, not too loud when cruising but if you open her up she howls. When installing it's okay to lift by the frame but before you tighten everything up make sure to ...

    Read More
    Helpful (7)

    Overall Rating 4.8 out of 5 stars
    Read All 37 Reviews

    Customer Photos (13) Submit Your Photo

    View All 13 Photos

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    5 Questions / 6 Answers

    Ask a Question

    would this gt catback fit on a v6 if you removed the stock y midpipe and ran a h pipe with long tube headers?


    • This will certainly fit if you purchase the MAC Off-road H-pipe that works with long tube headers we offer. I will post a link to this product below:


    Helpful (0)

    Hi, roughly what kind of hp/torque can I get from bbk headers, magnaflow street catbacks and flowmaster catted h-pipes ? Standard is 260/302. Thanks, Frank


    • Power gains will be different for each setup, for example; if you have BBK Ceramic Tuned Length Shorty Headers (96-04 GT) item #56101 ( with Magnaflow Street Catbacks and Flowmaster Catted H-Pipes you can gain around 15HP. If you have BBK Ceramic Long Tube Headers - Manual (96-04 GT) item #56010 ( with a tune you could see 25-30HP.


    Helpful (0)

    Will this system fit my 99 SVT Cobra Mustang?


    • The Magnaflow Street Cat-Back Exhaust will only work with the 1999 to 2004 Mustang GT and Mach 1. For your 1999 Mustang SVT Cobra you will want to purchase Magnaflow Cat-Back Exhaust Item #48011 (


    Helpful (0)

    Will this work with the sn95? Would this exhaust system fit the sn95? Can I just only modify the hangers so this setup can fit?


    • yes if it is from 99 to 04


    Helpful (0)

    Magnaflow catback exhaust installation? The actual color of my 2004 GT is Merlot Clearcoat, but that option was not listed. My question is: do you need any type of heat shield between the mufflers and the floor pans to keep the inside floors from becoming too hot? The original factory mufflers had heat shields attached to the top of them.


    • I have never had any problem with heat with any after market exhaust, never needed a heat shield


    Show 1 more answer Helpful (0)

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    Customer Reviews (37) Write a Review

    Overall Rating 4.8

    out of 5 stars

    Installation Time:Full Day

    Installation Cost:$100-$250

    • Loudness / Volume 4.130435 4.1
    • Exhaust Note 4.521739 4.5
    • Fit & Finish 4.434783 4.4
    • Bang For Your Buck 4.26087 4.3

    • 5/5

      November 29, 2009

      Fits and sounds great

      Put this on my 99 GT. Took a little effort to get it all lined up but it is doable. With stock h-pipe the sound was a little deeper and louder than stock but not much. I then added an off-road x-pipe. This increased the volume. The sound is deep. At idle, there is little difference from stock. But when on the gas, it sounds great. Definitely does not sound like Flowmasters. There is no drone or resonance while driving.


      Year: 1999 Submodel: GT

      Helpful (11)

    • 5/5

      June 29, 2010

      Very Nice Exhaust

      This kit is the best. The fit is perfect, not too loud when cruising but if you open her up she howls. When installing it's okay to lift by the frame but before you tighten everything up make sure to lift car but the differential so that you know the clearances are good. Very good exhaust for the money!!!


      Helpful (7)

    • 5/5

      November 18, 2009


      Awesome sounding Catback Exhaust setup.. I got this for my V6.. with O/R Pypes X pipe and BBK Shorty Headers. its an Awesome setup just need to Tune it now.. Overall Awesome Purchase.

      Joel Zervoulakos

      Helpful (7)

    • 5/5

      April 04, 2009

      New Exhaust

      Just got it installed yesterday great sound, better acceleration. Way worth the money.


      Helpful (7)

    • 5/5

      April 10, 2010

      Worth the price

      Put this system on my 2000 GT after replacing the stock h-pipe with a BBK o/r x-pipe. The sounds is much better than the chambered mufflers and I highly recommend it to anyone.


      Year: 2000 Submodel: GT

      Helpful (5)

    • 4/5

      January 06, 2009


      I just put these on my 2004 GT and man do they sound great! For my completely stock GT, it made it a little louder, but more muffled sounding. A new air intake or headers would help out the sound too. Install was kind of easy, but taking out the rubber grommets took forever. Overall, it took about 2 hours, but looks fantastic!

      matt w

      Year: 2004 Submodel: GT

      Helpful (5)

    • 5/5

      September 02, 2009


      Put this on my '99 GT along with an AEM cold air and the AM strut tower brace and my car has never sounded or run better. I'll be back for more parts AM...


      Year: 1999 Submodel: GT

      Helpful (4)

    • 5/5

      October 04, 2007

      Great Product

      I have this on my V6 mustang using the adapter available on this site. It looks wicked and sounds even better.


      Helpful (4)

    • 4/5

      Installation Time: Full Day

      May 21, 2012

      Sounds and works Great

      Had to get it installed at a muffler shop as I don't have a flat driveway or room in the garage. Added the PaceSetter V6 Dual Exhaust Adapter Kit in front of this on my 2004 V6. Works great, more power and better mileage.


      Year: 2004 Submodel: V6 San Jose, CA, USA

      Helpful (3)

    • 5/5

      Installation Time: Less than 1 Hour

      March 12, 2012


      i put this cat back on my mach 1 and with an off road h pipe and wow does it sound good, deep, loud, and just mean sounding


      Year: 2004 Submodel: Mach 1

      Helpful (3)

    • 5/5

      Installation Time: Shop Install

      January 03, 2012

      Great exhaust

      Great exhaust with an upgraded sound for your GT. I had a shop install it at the same time as my new clutch and it ran me about 550 together.


      Year: 1999 Submodel: GT Atlanta, GA

      Helpful (3)

    • 5/5

      August 18, 2009


      ive had them for about a month now and they are awesome. sound great feels better. worth the money.


      Helpful (3)

    • 3/5

      April 13, 2008

      Not Loud Enough

      I had these installed when i bought my GT and i have a friend that has a mid pipe with this catback system and it sounds pretty good.... but if your looking for your car to be LOUD this is not the way to go...


      Helpful (3)

    • 5/5

      April 11, 2008


      My 04 GT was pretty quiet stock. After i installed the magnapacks along with the magnaflow o/r tru-x x-pipe the car sounded like a beast. The exhaust makes the car sound like an old muscle car at idle, but at WOT it sounds really crisp. ITS ALMOST TOO LOUD!! 100% worth the money. I have no regrets. Id buy this product again and i HIGHLY recommend it.


      Year: 2004 Submodel: GT

      Helpful (3)

    • 5/5

      Installation Time: Afternoon

      January 26, 2016

      Awesome sound and quality

      I bought the magnaflows to replace my old flowmasters. Installation was a breeze! No more drone! Quiet when at idle but when you get on it, it sounds great!


      Year: 2000 Submodel: GT MA

      Helpful (2)

    • 5/5

      Installation Time: Shop Install

      Installation Cost: $100-$250

      February 24, 2015

      Magnaflow Catback Long Term Performance

      No rust or discoloration anywhere on the entire system after 8 years of use so you know this system will last. I like the etched tips that I can only get from Magnaflow. They replaced one of mine that got damaged as long I as provided proof of purchase so they don’t just sell them to anyone. Also you can swivel the hanger to center the tip before final install so it looks right. Get compliments, not complaints, from the neighbors using it with FFRP shorty headers and Bassani x-pipe. No drone and really quiet in the car above 2500 rpm on the highway which makes this system a keeper.


      Year: 1999 Submodel: GT Manor, TX

      Helpful (2)

    • 5/5

      Installation Time: Afternoon

      February 14, 2013

      Same great sound, no drone

      I had the magnapacks and for me with a daily driver the drone was just to much so i swapped to this catback kit and the problem was solved. It kept the same great magnaflow sound when i stepped on it, but there was no drone at cruising speed.


      Year: 2001 Submodel: V6 King of Prussia, PA, USA

      Helpful (2)

    • 4/5

      Installation Time: Shop Install

      Installation Cost: $100-$250

      October 14, 2017

      Deep Tone

      System is a little deeper than stock at idle, but gets louder when you get on the throttle. Slight drone from 1,700 - 2,100 rpms but quickly goes away. Great construction quality.


      Year: 2004 Submodel: GT

      Helpful (1)

    • 5/5

      Installation Time: Afternoon

      September 05, 2017

      Sounds good

      Installed on my 2003 Mustang GT sounds good nice-looking pipes but the driver side was kind of tricky kind of tight in that area but overall good product would recommend


      Year: 2003 Submodel: GT

      Helpful (1)

    • 5/5

      August 07, 2008

      Nice Sound

      I love the sound out of these Magnas.


      Helpful (1)

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