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SLP Loudmouth II Catback Exhaust (99-04 GT, Mach 1)

61 Reviews
Our Price

$517.99

  • Item #23017
  • MPN# M31007A

  • Market Price $559.99
  • You Save 8% ($42.00)
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Customer Photos
Features
  • Rich, throaty exhaust tone
  • Loudmouth II "bullet-type" race mufflers included
  • Versatile modular design
  • 2.5" 409 stainless steel tubing
  • 3.5" polished 304 stainless steel tips
  • Fits 1999-2004 GT, Bullitt, & Mach 1 Mustangs
Description
More Power and Sound. This SLP system includes SLP's famous Loudmouth II "Bullet Style" race mufflers for minimal restriction, increased horsepower and an aggressive tone, that are only second to the Loudmouth "shotgun" race resonators for sound.

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 bullet mufflers, the Loud Mouth II system is compatible with all SLP mufflers and resonators including the shotgun style Loud Mouth Resonators and the traditional-style PowerFlo Muffler.

Superior SLP Construction. This SLP Catback 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 II catback will bolt straight up to the factory Mid-Pipe without any extra modifications required on the 1999-2004 GT, 2001 Bullitt, or 2003-2004 Mach 1 Mustang to give it a rich, throaty sound.

Mustang Fitment: 1999 2000 2001 2002 2003 2004 Details

What's in the Box
Hardware included:
  • (8) exhaust system band clamps
Installation Info
Tech Specs
Catback 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 GT / Mach 1 / Bullitt Mustangs
Fitment
  • Bullitt - 01
  • Mach 1 - 03, 04
  • GT - 99, 00, 01, 02, 03, 04

Fits GT, Mach 1, and Bullitt

Most Helpful Reviews View All

Overall Rating 4.9/5 Write a Review
5/5
Great Muscle Car Sound

I am completely satisfied with the LM2. It has a nice muscle car sound. It has an aggressive sound while at idle but the pipes really roar when you start shifting through the gears. I would def. recommend

Read More
Helpful (9) (0)

5/5
SLP2

Overall, good sounding exhaust. Has a unique sound of any other cat backing exhaust. I put an off road X-pipe with my SLP2 it sounds very aggresive, and loud with a nice growl.

Helpful (7) (1)

Customer Photos (31) View All

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Q & A (2 Questions, 6 Answers) Ask a Question

Can this product fit under a v6? I have looked at the dual conversion kits for v6 on here and they aren't true dual conversions as far as I could tell. They use a y pipe..

halo14 Year: 2001 Model: V6

Question Resolved
Good Question (0) (0)
  • We offer both dual and true dual conversion kits: dual bolting up to the stock y-pipe and the true dual including an x-pipe with the catback. To answer your question, you can use this SLP Loudmouth System on your V6, but it will require the PaceSetter True Dual Adapter, which is an H-pipe adapter (please see link below). If you're looking for a true dual, x-pipe with catback, we carry a few by Pypes Exhaust: a Catted version, an Off-road version and a Catted with Turndown Tips. If you have any other questions, please don't hesitate to give us a call!

    Helpful (0) (0)

    LisaS Year: 1992 Model: GT

Show 2 more answers

any body have these with o/r h pipe ? i have lm1s with a mac o/r h pipe and was lookin for a better sound not just loud . how do the lm2s sound ? or whats a better resonator? i like it loud tho

sinko Year: 2002 Model: GT

Question Resolved
Good Question (0) (0)
  • I have these with an off road x-pipe and it sounds great. I had the resonators from the LM1s and it was crazy loud. I'm looking to try the mufflers from the power flo set next

    Helpful (0) (0)

    Ccmustanggt99 Year: 1999 Model: GT

Show 2 more answers

Reviews (61) Write a Review

  • 5 Stars .93 93%
  • 4 Stars .05 5%
  • 3 Stars 0 0%
  • 2 Stars 0 0%
  • 1 Stars .02 2%
4.9

out of 5 stars

60 Customers Recommend this Product

Installation Time:Afternoon

Installation Cost:$100-$250

  • Loudness / Volume: 4.578948 4.6/5
  • Exhaust Note: 4.894737 4.9/5
  • Fit & Finish: 4.842105 4.8/5
  • Bang For Your Buck: 4.789474 4.8/5
Filter By Sort By
  • 5/5 Yes, I recommend this product

    March 02, 2010

    Great Muscle Car Sound

    I am completely satisfied with the LM2. It has a nice muscle car sound. It has an aggressive sound while at idle but the pipes really roar when you start shifting through the gears. I would def. recommend this product to everyone!!

    CJ

    Helpful (9) (0)

  • 5/5 Yes, I recommend this product

    September 04, 2010

    Sounds Amazing

    I had a set of flowmaster super 40's on my Roush 360R before i put these on. I love the way flow's sound but everyone has it, and these SLP's surely made mine sound unique. It has a little bit of a raspy sound but not to where it's annoying or sounds aweful. Im really impressed with the system and i would suggest this to anyone who wants a slighly different exhaust note than every other mustang out there!

    Keith

    Driving Style: Daily Driver

    Helpful (7) (1)

  • 5/5 Yes, I recommend this product

    January 19, 2010

    SLP2

    Overall, good sounding exhaust. Has a unique sound of any other cat backing exhaust. I put an off road X-pipe with my SLP2 it sounds very aggresive, and loud with a nice growl.

    Andrew Gallo

    Helpful (7) (1)

  • 5/5 Yes, I recommend this product

    July 31, 2011

    03 Mach 1

    my dad got this set up for his mach 1, it roars when he starts it to go to work at 4am.. my neighbors say it wakes them up almost every morning! well worth the price

    Branden

    Year: 2003 Model: Mach 1 Driving Style: Daily Driver

    Helpful (4) (0)

  • 5/5 Yes, I recommend this product

    May 10, 2012

    sounds great

    The LM2 doesnt make alot of difference when used with a stock mid pipes and cats I liked it better after i had the slp x pipe installed sounds really good.

    Top 1000 Contributor

    John87

    Year: 2003 Model: Mach 1 Driving Style: Street / Strip 'Stangs I have owned: 1 Aiken, SC, USA

    Helpful (2) (0)

  • 5/5 Yes, I recommend this product

    December 11, 2011

    Remarkable

    Installed this exhaust in my driveway in about three hours. The installation was very straight forward and very rewarding. I replaced my flowmaster 40 series mufflers with this kit and the difference is night and day. Starting my car is a treat! Quality is excellent, and of course the slp tips are the best looking ones out there.

    Top 10 Contributor

    MineralGreyGT

    Year: 2002 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 1 Wilmington, NC

    Helpful (2) (0)

  • 5/5 Yes, I recommend this product

    April 19, 2009

    Good product

    I\'ve had this exhaust on my stang for over a year now and it has opened up more since I put it on. I am very happy with it. It\'s a clean tone and not raspy and while cruising it doesnt drone. Since I have put a new tb and plenum on the exhaust pops more but not too much. Wouldnt change the exhaust one bit.

    Brian

    Helpful (4) (2)

  • 5/5 Yes, I recommend this product

    June 01, 2012

    LOUD, and Muscle sounding

    MY FAVORITE PART SO FAR. Note: the clips didn't stay tightened all the way and I had my connections spot welded to make sure it stayed all together. This was most likely due to cold but better safe than sorry. When you start the car you really hear your Mustang for the first time. And if your car is still warming up it makes a wonderful kind of pop sound to your exhaust that just sounds mean. Not to mention once you get up in the rpm it just sounds amazing, Looks amazing, Sounds amazing, Just the fitting could be a tad bit better, but not a huge deal very minor.

    01GTSilverPony

    Year: 2001 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 1 Florida, USA

    Helpful (1) (0)

  • 5/5 Yes, I recommend this product

    November 25, 2007

    European killer

    I recently installed this on my 03 v6, the sound is killer. Many people have said that it sounds like a tuned European car rather than the typically expected ricer tone, I\'m extremely happy and even without the GT bumper it looks great!

    Raul arevalo

    Year: 2003 Model: V6

    Helpful (3) (3)

  • 5/5 Yes, I recommend this product

    May 17, 2008

    Exactly what I have wanted

    I just installed the SLP Loudmouth II Catback and I am very pleased with the sound. This is exactly what I needed to complete my car. Great sound! Makes it sound the way a V8 should sound. Deep tones that sound so good! Better than music!

    Rogelio De Anda

    Helpful (0) (1)

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