Free Shipping On Orders Over $49. Details

Talk to a Mustang Enthusiast
1-877-887-1105
M-F 8:30A-11P, Sat-Sun 8:30A-9P
Win $5,000 For Your Mustang! Enter Daily

SLP Loudmouth Cat-Back Exhaust (99-04 Cobra)

SLP Loudmouth Cat-Back Exhaust (99-04 Cobra)
$0.00
45 Reviews 10 Answers
Market Price $624.95 You Save 4% ($25.00)
Our Price

$599.95

FREE Shipping

  • Item 23005

Will this fit your Vehicle?

In Stock Ships same business day.
Ship to: Ashburn - 20149
Sorry, please enter a valid US or CA postal code
We're sorry, zip can't be updated at this time.
Add to Cart
Save for later
    Create a list
    Add to New List

    Saved - View your saved items

    We're sorry. We couldn't save this product at this time.

    Frequently Bought Together

    Features & Details

    • Rich, Throaty Exhaust Tone
    • Loudmouth "Shotgun" Race Resonators Included
    • Versatile Modular Design
    • 2.5" 409 Stainless Steel Tubing
    • 3.5" Polished 304 Stainless Steel Tips
    • Fits 1999 to 2004 SVT Cobra Mustangs

    Product Resources

    Customer Photos (13) Customer Reviews (45) Questions (7) & Answers (10)
    More Power and Sound. This SLP system includes SLP's infamous Loudmouth "shotgun" race resonators that offer virtually no exhaust flow restrictions to free up more horsepower and to produce the most aggressive sound possible.

    Modular Design.   SLP's unique modular design allows you to quickly and easily switch out the mufflers or resonators to suit your driving needs. Along with the included resonators, the Loud Mouth system is compatible with all SLP mufflers and resonators including the bullet-type Loud Mouth II and the traditional-style PowerFlo Muffler.

    Superior SLP Construction. This SLP Cat-Back system is made from mandrel bent 2.5" 409 stainless steel tubing for its excellent non-restrictive flow characteristics and long life. The system ends with a brightly polished 304 stainless steel 3.5" tips, that are electro-marked with the distinctive SLP logo, giving a great finishing touch and a show quality look.

    Application. Designed to be a direct bolt on, this SLP Loudmouth catback will bolt straight up to the factory Mid-Pipe without any modifications required on the 1999 to 2004 IRS equipped SVT Cobra Mustangs to give it a rich, throaty sound.

    Fitment: 1999 2001 2003 2004 Details

    MPN# M31006

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

    What's in the Box
    Hardware included:
    • (8) 2.5" exhaust clamps
    Installation Info
    Tech Specs
    Cat-Back Exhaust Specifications
    Piping Material: 409 Stainless Steel Tip Material : Polished 304 Stainless Steel
    Piping Size: 2.5" Tip Size: 3.5"
    Muffler Type: Straight-through Fitment: 1999-2004 Cobra Mustangs
    Will it fit my Mustang?

      Customer Photos (13) Submit Your Photo

      View All 13 Photos

        Questions & Answers (7)

        5 Top Rated Questions

        Hello do you know if I can put this on my 2004 mustang gt do you thing it will fit???

        • This exhaust is designed to fit a 99-04 Cobra only and will not work with a 2004 Mustang GT model. We do offer the SLP loudmouth and loudmouth II for the 04 Mustang GT which can be found here: https://www.americanmuscle.com/slpexhaust.htmland https://www.americanmuscle.com/slpmuloiica9.html. 

        Helpful (0)

        I have Kooks Headers and Kooks X Pipe will this bolt up together and not leak?

        • Hello, That is correct these are designed as a system.

        Helpful (0)

        Is this the LM1's or LM2's?

        • These are the LM1's.

        Helpful (0)

        SLP loudmouth or Borla ATAK?!?! and does this drone or sound bad w/o the resonators?

        • The SLP Loudmouth Cat-Back Exhaust feature a deep, throaty exhaust tone. The "shotgun" resonators that are included have virtually no restrictions which will offer more power and an aggressive sound. Without the resonators, you may receive a louder sound without some tone. The Borla ATAK Cat-Back Exhaust (99-04 Cobra), item # 29016, (http://www.americanmuscle.com/borla-atak-catback-9904-cobra.html) feature an extremely aggressive muscle car sound. These do not come with resonators like the SLP's do. Both of these Exhaust's should not feature drone.

        Helpful (0)

        Does the car need a re-tune with this catback? I have already have a CAI on the car.

        • The SLP Loudmouth Cat-Back Exhaust (99-04 Cobra) will not require a re-tune.

        Helpful (0)
        Post Your Question
        2 More Questions
        Do I have to install the resonators? Can I just leave out the resonators on this catback system so I can get more of a louder and throaty sound to this exhaust system? 2 answers
        Does this come with everything I need to install? Do I need any extra hangers or clamps or anything else with this system? 3 answers

          Customer Reviews (45) Write a Review

          Overall Rating 4.8

          out of 5 stars

          Installation Time:Less than 1 Hour

          Installation Cost:$100-$250

          • Loudness / Volume 4.794117 4.8
          • Exhaust Note 4.911765 4.9
          • Fit & Finish 4.735294 4.7
          • Bang For Your Buck 4.705883 4.7



          • 5/5

            Installation Time: Less than 1 Hour

            Installation Cost: $100-$250

            April 17, 2019

            SLP LM1 vs Borla Atak

            I just put on the SLP LM1 catback to replace my Borla Atak catback. I am running Bassani headers with the Bassani o/r X pipe. (American Muscle does not sell Bassani products for the 03-04 Cobras). The Borla Atak was too raspy and nascar racecar sounding at anything about 3k rpm's. I wanted deeper, throatier, more muscle car sounding sound. I LOVE the sound of the SLP system. Exactly what I was looking for. The Ataks are actually louder believe it or not, just not the loud I wanted. By all means the SLP is still very loud, just a different type of loud. Got compliments for both just personally like this sound better. Can't go wrong with either just know what type of sound you like. Both will wake the neighbors.

            Anonymous

            Year: 2004 Submodel: Cobra

            Helpful (0)

          • 5/5

            Installation Time: Afternoon

            August 23, 2018

            the beast has awoke!

            I have this cat-back exhaust paired with an O/R Bassani X-pipe and holy smokes! installation was a breeze. bolts right up. Highly recommend this exhaust if you are looking for loud.

            KingCobra

            Year: 2001 Submodel: Cobra

            Helpful (1)

          • 5/5

            Installation Time: Less than 1 Hour

            July 12, 2018

            Recommended to everyone thinking about this.

            Easy to install and definitely gave my cobra a real cobra sound. Definitely happy with my purchase!

            JamesC

            Year: 2001 Submodel: Cobra

            Helpful (3)

          • 5/5

            June 10, 2018

            2004 cobra

            The slps are really what I was looking for a great deep sound for the price I like better than most expensive brands turn heads

            QuintariusG

            Year: 2004 Submodel: Cobra

            Helpful (3)

          • 5/5

            Installation Time: Less than 1 Hour

            April 05, 2018

            Slp lm1

            Ordered on Wednesday on my door step by Friday fast shipping with easy installation, if you want LOUD this is the exhaust for you!

            Franky

            Year: 2004 Submodel: Cobra

            Helpful (3)

          • 5/5

            Installation Time: Afternoon

            March 21, 2018

            Very good exhaust would definitely buy it again

            It bolted on good no problems definitely will recommend to other people.

            MichaelF

            Year: 2003 Submodel: Cobra

            Helpful (4)

          • 4/5

            Installation Time: Afternoon

            March 05, 2018

            Awesome sound!

            Easy to instal with a friend and some good Tools. Great sound!!

            BruceUBB

            Year: 2006 Submodel: Other

            Helpful (3)

          • 5/5

            Installation Time: Less than 1 Hour

            February 27, 2018

            SLP LM1 EXHAUST

            If you want a loud and rasp sound this is the exhaust for you I have o/r-bbk x pipe with this setup man it turns heads and people love the sound

            Richard

            Year: 2004 Submodel: Cobra

            Helpful (3)

          • 5/5

            Installation Time: Afternoon

            January 08, 2018

            Perfect

            Can’t go wrong with this cat-back. Easy instal and sounds amazing. Just the catback it self was aggressive. I combined the set up with a BBK off-road X-pipe and now is a beast. My 99 Cobra finally sounds the way it should.

            Figgs

            Year: 1999 Submodel: Cobra

            Helpful (4)

          • 4/5

            Installation Time: Afternoon

            December 01, 2017

            Exhaust

            Good product. love the sound. Wish it was all ready polished for the price.

            MatthewW

            Year: 1997 Submodel: Cobra

            Helpful (3)

          • 5/5

            Installation Time: Less than 1 Hour

            November 05, 2017

            Perfect sounds

            I just installed this exhaust last night with my brother, we both didn’t think it would sounds as loud as it is. It’s perfect not to loud and deep, or quiet just the best sounding system.

            RichieJ

            Year: 2001 Submodel: Cobra

            Helpful (5)

          • 5/5

            Installation Time: Less than 1 Hour

            July 01, 2017

            Slp

            Excellent products.. Americanmuscle is the best....................

            Jhonv

            Year: 2001 Submodel: Cobra

            Helpful (4)

          • 3/5

            Installation Time: Less than 1 Hour

            June 26, 2017

            Not bad

            When I bought my 04 cobra it had a flowmaster cat back on it I needed something louder so I went with the slp. Although the slp is an improvement I'm still not 100 happy I plan on replacing the stock H pipe with an offroad Mac prochamber hopefully this will get the job done.

            EverettC

            Year: 2004 Submodel: Cobra

            Helpful (3)

          • 5/5

            Installation Time: Afternoon

            May 31, 2017

            Best mod I have done!

            I installed this system on my 2004 Cobra and I could not be happier. This is what a mustang should sound like! I did the whole thing in my driveway with the rear on ramps. I recommend following the instructions from American muscle rather than slp.com. The hardest part of the install was getting the old system out of the rubber hangers. System is tame at cruising speeds but really wakes up when you get on it. I like that I can still hear my super charger over the exhaust. All in all a great setup for the price.

            PatrickS

            Year: 2004 Submodel: Cobra

            Helpful (3)

          • 5/5

            Installation Time: Afternoon

            May 30, 2017

            SLP LOUDMOUTH EXPERIENCE

            It sounds awesome really woke up my 03 cobra.Everything I was looking for in an exhaust .

            DanielG

            Year: 2003 Submodel: Cobra

            Helpful (4)

          • 5/5

            Installation Time: Less than 1 Hour

            May 20, 2017

            LOUD

            MINE SOUNDED GREAT, WOULD RECOMMEND TO EVERYONE, GREAT JOB

            LesJ

            Year: 2003 Submodel: Cobra

            Helpful (3)

          • 5/5

            Installation Time: Afternoon

            April 06, 2017

            Loudmouth!!!

            I ordered this exhaust and it came with in days of placing the order. Installation was quick and simple only thing is I had to log into the SLP website to get the info but besides that I love the exhaust. The tone and note sound great, not to loud at low idle but once I hit it she screams. Combined with my x pipe its a great deal the price was not to bad either. I'd buy again..

            KerryL

            Year: 2004 Submodel: Cobra

            Helpful (3)

          • 5/5

            Installation Time: Less than 1 Hour

            April 04, 2017

            Great exhaust

            This exhaust is super loud I have long tubes and off road h pipe,I am going to buy the loudmouth 2 mufflers to quiet it down a little,the quality of this cat back is great though and fits great!!

            JeremyD

            Year: 2003 Submodel: Cobra

            Helpful (3)

          • 5/5

            Installation Time: Less than 1 Hour

            December 15, 2016

            Mean

            Sounds beastly, I was scared it was going to be too loud but it sounds perfect. Good solid deep tone and a nice crackle in the higher rpms.

            Kobietk

            Year: 2001 Submodel: Cobra

            Helpful (4)

          • 5/5

            July 19, 2016

            loudmouth

            Easy to install, good price and awesome sound!! Thanks AM

            JuanN

            Year: 2004 Submodel: Cobra

            Helpful (8)

          Related Mustang Categories