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Pypes The Beast Off-Road Exhaust (99-04 GT)

16 Reviews
Our Price


  • Item #20063
  • MPN# SFM27B

  • Market Price $688.99
  • You Save 10% ($69.01)
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Product Videos Customer Photos
  • Maximum Sound and Maximum Flow.
  • Includes Off-Road X-Pipe and Violator Cat-Back.
  • 409 Stainless Steel Construction.
  • Fits 1999-2004 GT Mustangs.
The Beast. The Pypes Beast kit for the 1999-2004 GT Mustang combines Pypes 409 Stainless Steel Off-Road X-Pipe with their 409 Stainless Steel Violator Cat-Back for Maximum Sound and Maximum Flow.

Pypes Off-Road X-Pipe. Pypes Mustang Off Road X-Pipe Crossover pipes are second to none when it comes to balancing out the exhaust gas pressure in your system. Constructed of sturdy 16 gauge 409 Stainless Steel tubing, each pipe bolts up perfectly in the stock position..

Pypes Violator Cat-Back. Violator Cat Back Exhaust from Pypes is the last exhaust system your 1999-2004 GT Mustang will ever need! The system is built to last, constructed from high quality 409 Stainless Steel. It features two Violator "Rude Sound" mufflers for Pypes ultimate in flow with an ultra aggressive sound.

Fitment: 1999 2000 2001 2002 2003 2004 Details

What's in the Box
  • (1) Off-Road X-Pipe
  • (2) Down pipes
  • (2) Muffler assemblies
  • (2) Over axle tailpipes
  • (4) 2.5" clamps
  • (2) Muffler hangers
  • (2) Tailpipe hangers
Installation Info
Tech Specs
Mid Pipe Specifications
Style Mid Pipe: Standard length "X" Type Headers Required: Shorty
Piping Material: 409 Stainless Steel Piping Size: 2.5"
Catalytic Converter: "No" - For off-road use only Fitment: 1999-2004 GT Mustangs

Cat-Back Exhaust Specifications
Piping Material: 409 Stainless Steel Tip Material : Polished 304 Stainless Steel
Piping Size: 2.5" Tip Size: 3"
Muffler Type: Chambered Fitment: 1999-2004 GT Mustangs
Will it fit my Mustang?
  • GT - 99, 00, 01, 02, 03, 04

Most Helpful Reviews

Attention getter

Have been running this system for about 6 months now and it will turn heads. I dumped it out right after the mufflers so I don't have all the extra piping over/after the axle. My favorite thing about this ...

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Helpful (1)


this system is verry loud and cackels and pops a lot if thats what ur looking for there is nothing beter if u want a good cruser that sounds good down low this is not the best thow. but when u get on it ...

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Helpful (13)

Overall Rating 4.7 out of 5 stars
Read All 16 Reviews

Review & Install Video

Hi I’m Justin with, and I’m going to be breaking down a system from Pypes they call “The Beast” fitting all 99-04 Mustang GTs. This system is actually a combination of a couple of different parts, first up we have Pypes’ violator series catback, paired alongside with Pypes’ offroad X-pipe. We used this exact system on our 98 bolt on build up, and let me tell you, the beast is a great description of the sound you get using this kit. Both the X-pipe and the catback are constructed using 409 grade stainless and feature mandrel bent 2.5” tubing, through those stainless violator mufflers, and all the way back to these 3.5” polished tips. Since you will be installing an X-pipe along with the catback portion, the install itself will be slightly longer at about 3 hours from start to finish, when it’s all said and done. Of course this factors in time for cutting off your factory exhaust as well, which will need to be done in order to perform this install. Now let’s hear how the beast from Pypes sounds compared to our factory exhaust.

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11 Questions / 10 Answers

Ask a Question

Exhaust Installation any reason this would not fit a 2001 Bullitt, manual trans?


  • As the Bullitt is a mildly modified GT, this exhaust should not have any fitment issues for your application.


    Good Answer (0) (0)

Show 1 more answer Answer This Question I need this answered (0) (0)

Do i have to use the tips? Do i have to use the tips that come in the kit or can i use different ones?


  • Looking at the Pypes web page, the tips are described as "slip fit," which would indicate they are not welded to the tail pipe. You should be able to use other tips.


    Good Answer (0) (0)

Show 3 more answers Question Resolved

headers? What brand headers are the best fit for this setup?


  • Stock manifolds or the JBA shorty headers.


    Good Answer (0) (0)

Answer This Question I need this answered (0) (0)

does this combo fit Flowmaster Ceramic Shorty Headers????


  • Yes it will fit. The short tune headers do not change the length required. You would only need to adjust the the mid pipe if you had long tune headers because of the extended design, which would require a shorter version mid pipe. If you have short tune headers this cat back is going to fit real nice!


    Good Answer (0) (0)

Answer This Question I need this answered (0) (0)

will this exhaust work with the stocks cats


  • The Pypes The Beast Off-Road Exhaust (99-04 GT) will come with a off road X pipe which would replace you cats with this straight through design. This kit will completely take away your cats.


    Good Answer (1) (0)

Question Resolved

Can I use any long-tube headers with this application? If not what can be done to make long-tube headers fit?


  • If you remove the downpipes in the Pypes The Beast Off-Road Exhaust (99-04 GT) you can attach long tube headers to the x-pipe, however you would need to do custom modifications to make it work.


    Good Answer (0) (0)

Question Resolved

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Customer Reviews (16) Write a Review

Overall Rating 4.7

out of 5 stars

Installation Time:Afternoon

  • Loudness / Volume 4.666667 4.7
  • Exhaust Note 4.666667 4.7
  • Fit & Finish 4 4
  • Bang For Your Buck 4.666667 4.7

  • 5/5

    Installation Time: Afternoon

    October 28, 2013

    Attention getter

    Have been running this system for about 6 months now and it will turn heads. I dumped it out right after the mufflers so I don't have all the extra piping over/after the axle. My favorite thing about this system is that at idle people might think that you only threw some random muffler you got from Autozone. It's not that loud. Where this system shines is when you really lay into it. The scream, crackle, and pop will get you attention and turn heads. The pricing is great. $600 for an o/r x pipe and full catback system in stainless steel.....You're not going to find that from any of the huge names like Flowmaster. Another reason I went with the Pypes system is that it seems like everyone in my area throws Flowmaster 40s on their cars and I wanted something different.


    Year: 2001 Submodel: GT Southern Indiana

    Helpful (1) (0)

  • 4/5

    August 02, 2010


    this system is verry loud and cackels and pops a lot if thats what ur looking for there is nothing beter if u want a good cruser that sounds good down low this is not the best thow. but when u get on it it unleashes a sound that could frighten wolfman


    Helpful (13) (1)

  • 5/5

    August 02, 2011


    I installed this on my 02 GT and like it alot. if your not looking for a really loud system dont go with this. because its loud... really loud. the kind of loud that draws attention. when i installed this i also did a sct tuner with a bama tune for my car. and it was awesome. probably the funest part is people giving that what the hell look as you drive by. because like i said its loud. only negative is the x pipe hangs lower than the rest of the car. my car is lowerd so speed bumps are a little scary these days. but oh well its still awesome.


    Year: 2002 Submodel: GT

    Helpful (9) (0)

  • 5/5

    December 28, 2009

    Pypes The Beast Exhaust System (99-04 GT)

    Preforms and Sounds Great. A round 5500 rpm and 110 mph I notice a big increase in HP my 4.6 sohc smoothed out began to accel with no noticable end in sight

    Jeff Gudgel

    Helpful (6) (1)

  • 5/5

    Installation Time: Full Day

    January 29, 2012


    Great product, fit was perfect! Absolutely love the angry sound my stang has now! Only hard part of the install on my 04 GT was the manifold bolt on the passenger side (pain in the @$$ to get off and back on. Other than that two rookies were able to fit the system perfect. Also, don't forget to get O2 extenders!! Thanks AM for kickin' @$$ and having the best deals!


    Year: 2004 Submodel: GT Toledo, OH

    Helpful (2) (0)

  • 4/5

    August 12, 2009

    The Beast

    little difficult to put in, but what exaust isnt? it sounds amazing and is VERY loud. well worth it


    Helpful (2) (0)

  • 5/5

    October 12, 2009


    love the sound, very loud

    angelo tornetta

    Helpful (4) (2)

  • 4/5

    October 20, 2010


    Absolutely amazing sound at full throttle! Only thing is its a pain to install and Im not sure if it was just me but it it seemed to not fit right, especially the x pipe. i had to get it welded but i would probably buy it again just for the sound!

    Matt W.

    Helpful (2) (1)

  • 5/5

    February 13, 2009

    Great exhaust.

    It just sounds awesome. It sounds like thunder going 60 to 65 mph down the expressway. Even at idle it sounds great. Would recomend this to anyone who wants a great sounding system.

    Daniel Hunt

    Helpful (1) (0)

  • 4/5

    November 15, 2009

    Great Sound

    The system sounds amazing once it is connected fully. I had to remove the stock studs out of the stock manifold on the driver side and use bolts to get it to fully seal (also, use the insert provided!!!) To do this I used a lift to get under the car comfortably and used a stud remover, one of the studs broke off flush but luckily I was able to drill it out without having to remove the manifold. Once it was on There was some bending involved and cutting, fitment was not very nice. But once the modifications were made and it was in and had good clearance all around it really does sound amazing.

    Brian Nelson

    Helpful (3) (3)

  • 5/5

    Installation Time: Full Day

    June 09, 2013

    pypes sound is definitely unique

    I replaced my flowmaster / magnaflow exhaust with the pypes beast with cats designed for shorty headers even though ive got long tubes. With some patience during installation the pypes rewarded me with a beautifully "unholy" sound at WOT.


    Year: 2000 Submodel: GT Wilmington, DE, USA

    Helpful (0) (1)

  • 4/5

    Installation Time: Afternoon

    July 29, 2015

    Pypes the beast

    The first week it was very loud. Necks would break and it just draws attention. Recently I've noticed a decrease in the loudness. I don't know if it's because I'm getting used to the sound but it is not the roar it was when it was first installed. Had it checked for leaks or any loose bolts buy nothing. Check engine light came on after the second day of installing. Will be picking up some eliminators soon.


    Year: 2002 Submodel: GT Duncanville, TX

    Helpful (0) (1)

  • 5/5

    August 22, 2016

    Great exhaust

    The exhaust kit fit perfect from front to rear. Very happy with fitment and clean look and very loud.


    Year: 2001 Submodel: GT

    Helpful (0) (0)

  • 5/5

    July 25, 2016


    I installed "The Beast" and it is a loud exhaust but not too loud for the daily driver! It's the perfect muscle car tone that all mustang owners want.


    Year: 2004 Submodel: GT

    Helpful (0) (0)

  • 5/5

    Installation Time: Afternoon

    August 22, 2015


    The exhaust is slot louder than I expected. But not just noise, a good loud u want from your stang. For the off road x pipe be prepared to take off the cats . Your stock h pipe will be removed therefore so will your cats. Keep stock parts for emissions. Great product


    Year: 2002 Aurora,co

    Helpful (0) (0)

  • 5/5

    Installation Time: Afternoon

    December 28, 2013

    The beast exhaust system

    The beast exhaust system sounds amazing, it was a little bit of a pain in the *** to install on the ground and the tips where a little difficult to got on but overall it is an awesome exhaust.


    Year: 1999 Submodel: GT

    Helpful (0) (0)

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