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Pypes Off-Road H-Pipe (99-04 GT)

Market Price $233.99 You Save 12% ($28.00)
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$205.99

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  • Item 20131
  • MPN# HFM16

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    Features, Video & Details

    • Improves Exhaust Flow for More Power
    • Classic Muscle Car Rumble
    • Pypes Modular Construction
    • For Off-Road, Track Use
    • 2.5" 409 Stainless Steel Tubing
    • Fits 1999-2004 GT Mustangs

    Review & Installation Video

    Review & Install Video

    Improves Flow For More Power. Add even more horsepower and torque to your 4.6L GT Mustang by eliminating those power robbing factory catalytic converters with a brand new Pypes Off Road H-Pipe. The Pypes off-road H-pipe will significantly improve your Mustang's exhaust flow for a notable increase in horsepower and torque.

    Muscle Car Rumble. This free flowing Pypes h-pipe for the GT Mustang will not only increases power, but it also adds a deep muscle car rumble to the sound of your exhaust with its classic "H" crossover pipe design.

    Modular Construction. Pypes unique three piece modular construction makes it quick and easy to add or remove catalytic converters to your exhaust system in just minutes, depending on your driving needs.

    Durable Stainless Steel Construction. Pypes uses sturdy 16 gauge 409 stainless steel mandrel bent 2.5" tubing for improved exhaust flow and features welded reinforcement plates for additional strength.

    Application. This Pypes Off-Road H-pipe is designed to be a direct bolt-on for the 1999 to 2004 4.6L GT Mustangs with either aftermarket short tube headers or the stock manifolds and a dual catback exhaust installed. Intended for off-road, track use only, does not include catalytic converters.

    Fitment: 1999 2000 2001 2002 2003 2004 Details

    What's in the Box
    • (1) Two-piece H-pipe
    • (2) Down Pipes
    • (2) Clamps
    Installation Info
    Tech Specs
    Mid Pipe Specifications
    Style Mid Pipe: Standard length "H" Type Headers Required: Shorty or Stock Manifolds
    Piping Material: 409 Stainless Steel Piping Size: 2.5"
    Catalytic Converter: "No" - For off-road use only Fitment: 1999-2004 GT Mustangs
    Will it fit my Mustang?

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    38 Questions / 14 Answers

    Ask a Question

    How is the sound? I'm thinking of buying this h-pipe but I can't decide. I want a loud exhaust note but I don't want it to be raspy. I think the x-pipe would make my flowmaster 10 series too raspy, would the h-pipe be better? Thanks!

    chevyeater

    • The h-pipes are known to give off a deeper, more classic muscle car sound while x-pipes tend to give off a raspy, more exotic high pitched note. If you want a loud and deep exhaust note, go with the off road h-pipe...you won't be disappointed. It will definitely be a better match to your flowmaster 10's.

      Brian89

    Show 4 more answers Helpful (4)

    Is there any reason why this should not fit a 2003 Mach 1. I was under the impression the mid-pipes for the GTs and Mach1s were the same. Thanks.

    Ryan

    • You are correct! They are the same. You shouldn't have any issues fitting this to a Mach 1

      MachRMan

    Helpful (1)

    Can you still reuse your O2 sensors on this midpipe?

    warewolf39

    • You should definitely be able to reuse your factory 02 sensors with this midpipe. However, because the cat's are gone you will need to purchase a set of mil eliminators to go in line with the rear O2 sensors in order to avoid the check engine light.

      Luckstone

    Show 4 more answers Helpful (1)

    Does the O2 Sensor Ports come pre-threaded? I read a review that said they don't....

    CalebKoki

    • The Pypes Off-Road H-Pipe will come with threaded oxygen sensor bungs.

      AshleyK

    Helpful (0)

    Would this H-pipe sound good with SLP Loudmouth catback that I currently have on my car? I currently have a MAC pro chamber mid pipe and I don’t like the sound, but I can’t tell if it’s the catback or the mid pipe that would make the difference. I feel like there’s too much blat blat blat noise instead of more of a classic deep muscle car sound.

    SergioADM

    • This Pypes Off-Road H-Pipe and other traditional h-pipe will provide that classic deep muscle car sound. Every exhaust component will change the sound, however, the mid-pipes especially on a vehicle with stock headers will cause the most noticeable sound change. We would recommend listening to a few exhaust clips of this h-pipe to ensure it is something you would like.

      AMJEFF

    Helpful (0)

    How can I get this installed since no shop wants to touch catless pipes? Anyhelp appreciated

    CharlieP

    • Installation of the Pypes Off-Road H-Pipe requires light to moderate mechanical skill and should approx take 2 hours for the installation. The installation requires basic hand tools and a cutting device. I will include an installation guide below if you would like to try it out yourself, if not I would recommend going to a local mustang shop or performance shop. https://www.americanmuscle.com/pypes-or-hpipe-9904gt-manu-install.html

      Rob S

    Helpful (0)

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    Customer Reviews (88) Write a Review

    Overall Rating 4.6

    out of 5 stars

    Installation Time:Full Day

    Installation Cost:$100-$250

    • Loudness / Volume 4.609756 4.6
    • Exhaust Note 4.792683 4.8
    • Fit & Finish 4.463415 4.5
    • Bang For Your Buck 4.731707 4.7



    • 5/5

      Installation Time: Full Day

      April 13, 2018

      Awesome

      Hard to take out the old stock H pipe but easy to install the new aftermarket one. And I would recommend it over the stock H pipe because it gives it a deeper tone

      DannyK

      Year: 2001 Submodel: GT

      Helpful (1)

    • 4/5

      Installation Time: Afternoon

      March 05, 2018

      Works!

      Good setup for the price, 4 piece design makes it easier to install. Didn't include longers studs to the axle back portion. maybe my axle back was not stock but I don't think so. The stock studs from my axle-back's where too short. Ended up with some stuff from the hardware store. Not a big deal though, they where rusty anyway. Don't be surprised if it takes you all evening to install without a lift. Getting everything into position is kind of a pain. I used some exhaust gasket maker around each fitting for a real good seal and it's held up well.

      EricK

      Year: 2001 Submodel: GT

      Helpful (2)

    • 5/5

      Installation Time: Afternoon

      February 28, 2018

      Classic Rumble

      By far my favorite modification that I have done to the car so far. The previous owner installed a set of Flowmaster 40 series mufflers, but kept everything else stock. I really love the classic sound of the Flows, but I felt that the exhaust flow was being stifled before the mufflers, and wanted to have more distinction and a better exhaust tone. I used a Bama X4 tuner to turn off the rear O2 sensors, and install took about 4 hours on the cold garage floor. Car is now much louder, but has the classic muscle sound I was looking for. At idle, the lope is amplified, but is not overwhelming. But stab the throttle, and God himself will take notice. I did not experience ant real fitment issues, although my drivers side exhaust tailpipe sticks out a little farther after the install. Not a big deal, only between a 1/4" and 1/2" of difference between the tailpipes. No leaks that I could make out, but this was probably due to the fact that I used an electric impact wrench to tighten everything down. In addition, I would advise against expecting a huge performance increase after installing this product. A mid pipe will generally net you 6-12 hp at the crank. Considering that this is a less than 4 power increase from stock power for a GT, you will likely never notice it.

      Andrew

      Year: 2002 Submodel: GT

      Helpful (2)

    • 5/5

      Installation Time: Afternoon

      February 28, 2018

      Worth The Money

      The product itself is very well made and worth the money. It took me 3 days to install due to dufficulty getting the manifold bolts off but went on easy after that. The kit does not include the extended hardware needed to mount to the cat-back but $5 at the hardware store and she sounds like a real muscle car now :)

      CalebKoki

      Year: 2003 Submodel: GT

      Helpful (2)

    • 5/5

      Installation Time: Afternoon

      February 10, 2018

      Amazing !!!!

      I have the Pypss M-80 and after installing this Off road H pipe from Pypes exhaust as well my car sounds beyond amazing ! Highly recommend !

      JP

      Year: 2003 Submodel: GT

      Helpful (2)

    • 5/5

      Installation Time: Afternoon

      February 08, 2018

      Perfect

      Fits perfectly to the headers, and gives off a really nice exhaust note. Deep, but loud. I have it paired with the SLP loudmouth catback and, oh man, its ridiculously loud now. Great product from pypes

      KyleF

      Year: 2001 Submodel: GT

      Helpful (2)

    • 5/5

      Installation Time: Less than 1 Hour

      December 15, 2017

      Pypes !! Awesome sound

      Made my Mustang gt sound like a beast!!! One of the best upgrade I have done , not too loud inside of car, has that old Muscle car sound, love this as much as my 410 gear But back to the pypes I go to alot of shows the old timers tell me how good it sounds

      Mustangshane

      Year: 2002 Submodel: GT

      Helpful (1)

    • 5/5

      Installation Time: Afternoon

      December 04, 2017

      Sounds good now

      Simple to install. Look good and sound great. Cant wait to put some Flowmaster on them

      TXH

      Year: 2004 Submodel: GT

      Helpful (1)

    • 5/5

      November 21, 2017

      Great sound at higher RPM

      This H pipe sounds great on my '02 GT. Not much of an increase in sound at an idle but at the upper ends of the shifts it sounds excellent. I have had many complements from neighbors (at least 5 Mustang owners on the block). I also purchased the MIL eliminators at the same time and they too work as advertised...no check engine lights. I would highly recommend this purchase and especially from American Muscle. I have had outstanding service and support with every purchase I've made. I purchased these pipes (and other items) from A.M. and the shipping is the best I’ve ever experienced.

      CameronG

      Year: 2002 Submodel: GT

      Helpful (2)

    • 4/5

      Installation Time: Afternoon

      November 11, 2017

      Good pipe, installation weird

      The pipe sounds great, but it was kind of a hassle to install. If you have a GT then theres an extra sleeve type thing you have to put on the driver side at the headers. Without it you'll have a pretty big exhaust leak, but even with it im getting an exhaust leak (although this is probably mostly bc im very new to this but that also goes to show its not that intuitive). Going with an offroad pipe is gonna give you a bad smell around the car. This pipe gives a highway drone thats unnoticeable at 55, but at 70 its terrible. The sound really opens up at 2500 rpm.

      JoshL

      Year: 2003 Submodel: GT

      Helpful (2)

    • 4/5

      Installation Time: Afternoon

      November 09, 2017

      pypes h pipe exactly what the doctor ordered

      Here's my experience with the pypes off rd h-pipe. My kit was missing the down pipe sleeve. This took a week to rectify. This despite Pypes checklist in the box for the packer to sign off on each part as it is boxed. I also called Pypes tech support to inquire about using factory bolts, which they assured me I could reuse. This was mentioned by several reviewers.Well useless advice as no way to reuse factory fasteners. I was able to buy some nice 7/16 bolts (3") and that's the way to go. Some reviewers used 3/8 bolts and they are not beefy enough. I got it installed and it did require quite a lot of adjustment to finally stop the leaks. Also the right side down pipe just barely clears the body. If it was any closer I would ask for another. I used Walker 2-1/2" lap joint mega-clamps on the down pipes and a 2-1/4" on the h-pipe as the supplied clamps are cheap and prone to leak. I only use these clamps on exhaust jobs. Do yourself a favor and spring for these, they are simply amazing and strong. The aft end of the H-pipe required some hammering to get them smooth and round. Now for the result.... Awesome!!! I did my research and it payed off. If you like the raspy rattle snotty exhaust note, this is not your item, get yourself an x-pipe. I am using factory mufflers no cats. I see other reviews have said this pipe is everything from obnoxiously loud to same as factory h-pipe with cats. I can't explain that but I find it 10-15 louder with the note very similar to stock at Idle. Nice. When you're on it it is much louder but very nice and no drone at 65mph. It sounds great, ballsy, and is the best price I could find on web. Great tasteful muscle car rumble. Gotta have one.

      TonyK

      Year: 2000 Submodel: GT

      Helpful (3)

    • 5/5

      Installation Time: Less than 1 Hour

      November 09, 2017

      Astoundingly Great!

      Great pipes! Well made! This will definitely make your current exhaust 3 times louder!

      OmarM

      Year: 2002 Submodel: GT

      Helpful (1)

    • 5/5

      Installation Time: Afternoon

      October 22, 2017

      Great install

      Sounds amazing and can feel the difference over the stock h pipe. Fit mostly well. Don't forget the downpipe gasket!

      DavidC

      Year: 2004 Submodel: GT

      Helpful (2)

    • 5/5

      Installation Time: Afternoon

      October 10, 2017

      Awesome sound!

      Fast delivery and pipes sound perfect, easy install.

      ToddL

      Year: 2003 Submodel: GT

      Helpful (2)

    • 5/5

      Installation Time: Afternoon

      September 29, 2017

      GREAT SOUND!

      I've wanted these for years but was afraid they'd be too loud. Well, I was wrong! They are loud but only when you want them to be and I haven't stopped smiling since I put them on! I also have the super 44s and its a great sound! If you bought a Mustang because you like that sound, you will be kicking yourself you did not buy these sooner!

      Dono

      Year: 2003 Submodel: GT

      Helpful (1)

    • 4/5

      Installation Time: Afternoon

      September 19, 2017

      Great Kit

      Fits ok, looks good, Sounds awesom, I was happy I went with the H instead of the X. Only wish it included the required bolts to clamp to existing exhaust, and a new gasket for the passenger side. But overall great product !

      DerrickA

      Year: 2002 Submodel: GT

      Helpful (5)

    • 3/5

      Installation Time: Shop Install

      Installation Cost: 0-$100

      September 17, 2017

      Works

      Customer service from AM is great as usual. As far as the midpipe...leaks a little in various places. Either weld this up or spend a little more for something better. Ended up pairing this with American Thunder catback. Sound is epic! Performance gains...meh... gas pedal feels a little lighter but, no big power difference.

      KyleS

      Year: 2001 Submodel: GT

      Helpful (2)

    • 4/5

      Installation Time: Afternoon

      September 06, 2017

      Great H pipe

      Took about 2.5 hours to install. Ran into one issue with the passenger side pipe was hitting the floor pan. Had to be bent a bit to fit right. Other than that, things went smooth and gave my stang a great sound paired with the Violater cat back.

      Brett

      Year: 2003 Submodel: GT

      Helpful (2)

    • 5/5

      Installation Time: Afternoon

      September 02, 2017

      Amazing sound.

      I love it. My stang sounds more loud just like I wanted it to be.

      Bob

      Year: 2001 Submodel: GT

      Helpful (2)

    • 4/5

      Installation Time: Afternoon

      August 26, 2017

      Stock 2001 GT w/ Pypes off road h pipe

      I ordered this off-road h pipe a week ago and received it a few days later. I had a local exhaust shop put it on which came out to 79.50, not bad. This H-pipe sounds so much better than the stock h pipe! When you start the car up it is noticeably louder and deeper. I still have the stock mufflers on but will be putting super 44s on soon. It is decently quiet below 2k Rpms but after that it gets pregesssivly louder and sounds amazing. Puts a smile on my face everytime. Pretty loud so you will turn heads no problem! If you still have that stock h pipe, get this and you will be very happy garunteed.

      RandyG

      Year: 2001 Submodel: GT

      Helpful (4)

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