Everything You Need To Know About Your 94-04 Mustang’s Exhaust

Everything Exhaust

Ok guys, heads up – I’ve broken this article down by exhaust component to cover as many of our common Mustang exhaust questions as possible. If there’s a question you have that isn’t answered here, then you know what to do! (If you’re scratching your head right now – the answer is call/email us!) You can also check out our tech article on Understanding Mustang Exhaust Systems if you need a refresher or some basic info.

How does an aftermarket exhaust improve my car’s performance?
I’m sure many of us are familiar with the “air pump” analogy – that is, an engine is essentially a big air pump, and the faster we move air into and out of the engine, the more power it will make. Therefore, replacing your factory exhaust with a larger, freer-flowing aftermarket exhaust can improve horsepower and torque.

What’s the difference between long-tube and shorty headers and how do they help my car?
Long-tube headers can also be called full-length headers, and require a shorty mid-pipe, oxygen sensor extensions, and a tune. Stock manifolds restrict airflow, especially on 2-valve engines. Tuning is required because long tube headers relocate the oxygen sensors further down-stream than factory, so a tune is necessary to compensate for the delay in response. For all you track-rats out there (or anybody who’s looking for a little extra kick from your pony) – long tubes are the way to go. Shorty headers are a direct replacement for your factory exhaust manifolds and do not require additional parts or tuning. Power gains differ between the two as well; long tubes will see the most gains in the mid-low to mid-high RPM range, while shorty headers will see their biggest gains in the mid-RPM range. Shorty headers are a great upgrade for your daily driver, but long tubes are best if you’re going for all-out performance, on the street or the strip. Another option for your Mustang headers is ceramic coating, which is more durable than chrome, and absorbs heat better.

Why are there so many different mid-pipes and which one is right for me?
Mid-pipes come in 4 flavors – they are either X-pipes or H-pipes and come in standard length and “shorty” length. The “X” and “H” refer to the shape of the pipe, and which length you need depends on what headers you have on your Mustang. As I said above in the header section, long-tube headers require a “shorty” mid-pipe whereas shorty headers require a standard-length mid-pipe. If you don’t have aftermarket headers and are looking to upgrade your mid-pipe, the standard-length pipe is what you’re looking for. A Mustang X-pipe provides slightly more horsepower than an H-pipe, because it provides the “path of least resistance” for the exhaust gas to travel; but X-pipes often lend a higher-pitched, raspy note to the exhaust sound. Mustang H-pipes encourage the exhaust gas to “tumble” more, which gives H-pipes more of a rumble, with a slightly deeper tone. Ultimately, sound is a matter of opinion and some folks will sacrifice a few hp for a sound the prefer whereas others make hp their priority.

The mid-pipe is also where the catalytic converters are located, and most mid-pipes are offered “catted” and “off-road”; if your state requires a vehicle emissions test then we strongly recommend using a catted mid-pipe. Notice I haven’t mentioned anything about running straight-pipes from the headers to the back of the car – the reason is that this is not good for the engine’s performance. Mustang exhausts were designed with a crossover for a reason; the crossover helps to equalize exhaust pulses and back-pressure between the two banks of the engine, and it’s vital to maintain the crossover to keep your engine running correctly.

The section of the exhaust known as the “cat-back” contains the mufflers and runs from the mid-pipe back to the tail-pipes. There are a few things to keep in mind when you’re looking for a cat-back exhaust. Ford used 2 1/2″ piping that reduces to 2 1/4″ for most exhausts, whereas aftermarket pipes are 2 1/2″ throughout. Make sure you check the specs for each manufacturer, though, because some use a 2 1/2″ tip and some manufacturers offer kits with a 3″ tip, instead. Your Mustang’s mufflers are the biggest determination of your Mustang’s exhaust sound; there are basically two types – chambered and straight-through (aka – resonators). Chambered mufflers route the exhaust gas through a system of chambers and passages to muffle the sound. They are slightly more restrictive, but offer a quieter sound. Straight-through mufflers, or resonators, route the exhaust gas straight through the center of the muffler and are extremely loud. Each cat-back has a unique sound (depending on the manufacturer, muffler type, and presence of cats), so check some videos out online before making your decision.

What kind of exhaust should I put on my V6?
If you’re looking for a more aggressive sound, you’ll want to convert to a true-dual exhaust. AmericanMuscle offers V6 Dual Exhaust Conversion kits in catted and off-road varieties that allow you to use a GT cat-back, giving you more cat-back options to choose from. Many V6 owners are concerned with the dreaded V6 drone, or installing an aftermarket exhaust and ending up with a Mustang that sounds more like a Mini. If you want don’t want that raspy, high-pitched sound and possible drone, avoid straight-through mufflers and resonators. Converting to a true-dual system will give you a much better sound than just installing aftermarket mufflers.

Alright folks, that’s all the time we’ve got for today! Tune in next month to see what’s new in the world of Q&A with Heather, and remember – if you have any questions that weren’t answered this time around, you can call or email us and one of our Mustang experts will be able to help you out.

  • http://www.solidhex.com Patrick

    Nice write up! So ultimately, which would you recommend going with if you had to choose between doing a cat-back exhaust or axle-back exhaust, assuming you are leaving all the rest of the exhaust components stock?

    • http://www.americanmuscle.com/ Heather

      It depends on the year, 05-09 an axle-back would do just fine, however, I’d recommend a cat-back on the pre-05 models. :)

      • Dustin

        Axle back is for 05+ cars only. This is because of the exhaust systems design is totally different the previous mustangs were the mufflers are under the back seat.

        There is no such thing as axle back for anything pre 05.

        On 05 and later its just a muffler swap and the last bit of pipe then the exhaust tip.

        Again just differences in the exhaust setup.

  • Norm

    For the V6, you can do straight through axle backs combined with midpipe resonators.

    Check this out.


    • http://www.americanmuscle.com/ Heather

      Thanks for the input, that exhaust sounds great! :)

  • Cort

    i have straight through mufflers on my v6, it is not high pitched or raspy at all. its got a good low rumble. i love my straight throughs!!

    • Sean

      Thats what I have on my 02 v6 and it sounds great. I get compliments all the time. Straight pipe exhaust by flowmaster. Not sure where it came from, because I bought the car with the exhaust already on it.

  • http://www.solidhex.com Patrick

    I have a 2010 GT. I’m really thinking about ordering the Magnaflow Magnapack from ya’ll 😉

  • Larry

    I’ve often wandered about upgrading the stock exhaust on my 98 GT and this is going to sound weird, but – I do NOT want it loud. I like the way the stock exhaust sounds, though I would like to eliminate some of the freeway drone of it. I live on a busy street and sometimes I get motorcycles that sit at the light and rev… I just want to go out there and ask then just how small their (you know) is. 😛

    • Ken


      I added a Magnaflow Catback Exhaust to my 98 GT several years ago. This system has a very nice tone. It is not loud and obnoxious. It will get a little louder when you open the throttle up but down low, it has a very nice rumble. I have received numerous compliments on my exhaust. If you are looking for an aftermarket exhaust with a nice deep tone, that is not obnoxious, go with Magnaflow. Plus it looks great too!

  • Ernesto Sr.

    What would you recommend for a 2002 Ford GT Mustang Convertible? Please list Part Name/Price.
    I am obviously not “mechanically inclined.” However, I do love my Pony and would love to help it breath, if it is going to produce a mean (not too loud), intimidating rumble. Nothing near what the Motorcycles and/or Imports do. I agree with Larry that the Tiny P…. Syndrome (AKA TPS) Is getting ridiculous and a Pony is about the only solution to quiet them down a bit.
    Please be as precise as possible. I am taking you advice seriously and need to know what I am looking at in price for a quality Exhaust system.

    • Corey

      On my 2001 GT Mustang I did pypes shorty headers, BBK x-pipe and SLP Loud mouth 1 cat back system for a MEAN sounding GT. It cost around $1,400 And that was including a $200
      header install for the headers from Ford. I’m in Germany with the car now tho
      and the Germans always ask if it’s a GT 500 and tell me it’s a bad ass sounding

  • Shawn

    Just an FYI. I have an automatic 02 mustang GT and got the long tube BBK headers with the short SLP H-Pipe and SLP Loudmouth exhaust. Needless to say it sounds like a beast now. But when I went to put the long tube headers in at first, the placement of the oxygen sensor was FUBAR because my Transmission pan was in the way. I ended up having to weld the original hole closed and make a new on on the outside for it to fit. I don’t think the long tubes were made for automatics, but like i said it worked out (with a little elbow grease) and sounds like animal too. :)

  • Kyle

    Heather…..Will You Marry Me!?!?!?

  • Greg

    Yes, all long tube headers listed on this site say either “MT only” or “Coupe only”. No long tube says it will work with AT convertible, which I have. Bummer! Doesn’t SOMEONE make one for us?

    I’d love to see AM carry the Dynomax VT, since it has a valve that makes it really quiet and drone free, but opens up when you get on it. Any plans?

    Also, as a suggestion to American Muscle, can you rate all the cat-back exhausts on a list from LOUDEST to QUIETEST? You have to click on each one to see it’s loudness rating. It would be easy to have a nice, simple list that showed them all.


    • Cory

      Actually i guess Flowtech makes LT headers for us 99-04 automatic, convertibles… check it out on summit thats the only place i seen

  • Tim

    I just want info about headers for a 351 swap into an SN95 car, more sepcifically what headers I can use (long or short) that won’t require me to hack the headers, or antying on my Stang (a Cobra). It seems like using fox swap headers will require just that, and I have yet to see anyone offer SN95 specific 351 swap headers f/s. What shorty headers did Saleen use on the ’94-’98 S-351s, and are those still available?

    • Clyde Beddoe


      Your best option for a street car would be shorty headers and 2 1/2″ pipes
      Unless you are running at high RPM’s all the time, there is not much gain from long tube’s
      Check for an exhaust for a 1995 351 Mustang, Ford did make a few. They might be Cobra’s.
      Anytime I need parts I just tell them I have a 95 351 mustang.
      Check Ford Racing if they have what you want, the parts always fit.
      Go to the Saleen Owners and Enthusiast Club (SOEC.org) there are spec sheets there.
      Saleen sold all the old parts a few years back.
      If you watch e-bay some stuff pops up now and again but beware alot of fakes out there.

  • Fabian

    I have a 2004 V6 and I’m looking for a deep but quiet V8 style rumble sound. What can I do?

    • Blake

      @Fabian, check out some Mac long tubes ($300-$370), you can get them from stangmods.com. Do a shorty catted midpipe, and then add flowmaster 50’s catbacks. They still have the great flowmaster sound when you get on it but when idling or cruising they’re pretty quiet.

  • michael

    hey heather i have hade lots of mustangs but only 2 of the 4.6 mustangs but have hade 26 of the older fox body mustangs 87 to 93 use to buy them to fix them up and put them back out on the road . just got a order shipped in today from you guys infact i have to call in and ask some questions about it but any ways on my 5.0 style mustangs i have went with so many different headers and mid pipes and cat backs its crazy but i found with the long tube headers i lost alot on the bottom end and just felt like it didint have the power . but with the shorty headers they where great off the line and mid range . why do you think this ? on my 2000 mustang i have now i went with the shorty headers and x pipe because my 02 i hade the long tube headers to try to see if they worked better with the 4.6 but it was the same case why do you think i was getting more power off the shorty headers.. shoot me an email id love for you to hear the car not i have no idea why it sounds like it does i have hade people pulling out of the parking space and stop and get out and ask me what i hade on the car for exhaust even the guys at the track say the same thing it wont sound the same when i send it to you on the computer but you will see what iam saying it just sounds diffreint its great people say it sounds like the car on the tv for the zmax oil. which leaves me on installing my super charger the company dont have the tune for the off road x pipe so want me to put the stock one back on but i just cant do it the car sounds to good shoot me an email at m7rhodes@aol.com and ill send you a file so you can hear it and tell me what you think i have the traney out and the clutch pulled out was waiting on the parts to come in from your company

  • Keith

    Great writeup; I’m a regular customer of AM. Email today from AM reminded me that I want to make another change to my ’03 GT vert. with CAI, 78MM TB, tune program, underdrive pullies, JBA shorties, high flow catted midpipe. Are there any sites that will let me hear and compare sounds from exhaust manufacturers, like Magnaflow and Flowmasters? The former owner of my ‘stang had put “V-Thrust” mufflers (I dont even know of that brand). However, there is terrible droning from 2K to 3K RPMs that I want to eliminate. Any help would be appreciated.

    • Wayland

      Second Skin Audio has some products that may help. It’s just another option. They’ve got some neat stuff.

  • http://aol william eastwood

    I have a 94gt with xpipe and dynomax bullits that dump before the rear axle and the ole 5.0 sounds great . But really enjoy the info you ll put out , keep up the great work . THANKS AMERICAN MUSCLE keep on stangin!

    • JerkyBoy

      man i would like to have one of those 94-95 5.0 liters…

  • http://stangsgonewild timmy Bradley


  • http://www.imagineautoworks.com THE BOSS

    I purchased bbk longtube ceramic headers and a bbk x-pipewith flowmasters. The horsepower is great but definately gives a little higher pitch to thesound.

    • http://www.imagineautoworks.com THE BOSS

      ALSO its a 99-04 GT

  • Kyle

    To michael post I’ve sat through many dyno runs with UTI schooling an have found the collector has found the biggest gain for HP that’s because of the pulse width of each cylinder don’t be scared try new collectors trust me!!!

  • Jim

    My only question, whom noone has been able to answer todate, is this, “Will the GT Cat Back system utilize the area along the inside of the frame when installed?” If so, “Will the pipe on the right side interfer and/or ‘boil’ the gas line that is running parrell to the pipe?” I have been told by severl muffler shops in the area, who have refused to install the duals, that that is the reason. However, one other shop said that they woul install duals but would not gaurentee the installation with respect to the “boining” problem. I have seen several older V6 Mustangs in the area with duals, but could never seem to be able to converse with them. Going in opposite directions most of the time. I would still like to install duals but due to the problem above, I am reluctant to do so.

  • Clyde Beddoe

    PA: 15 years for Classic tag = no emissions
    headers, off road pipes, and mufflers
    no cats no air pump
    Sounds and smells like a car should

  • Óscar Robles

    Ok, i got dual exaust on my 00 v6 and straight-pipes. What damage can it make to the engine?

    • Andrew Barbour

      If you have found any answers, I would love to hear them. We have the same issue with our 2000 V6

  • CJ

    What about Mac’s Prochamber?? i have bbk ceramic shortys to mac prochamber to flowmaster 40’s or 44’s. not sure whitch. but it sounds great

  • http://www.newyorkmustangs.com NewYorkMustangs.com

    Very informative. I love my exhaust setup. MAC Long tubes, o/r H-pipe and Flowmaster American Thunder cat back.

  • Andrew Barbour

    My son has a 2000 V6 with BBK Shorty headers, no cross over into a dual magnaflow. We bought the car with the magnaflow on it. I had the same stock car a few years ago. The stock car seemed a little quicker. I guess it might be the lack of back pressure because of the straight pipes. We just installed the BBK shorty headers and a BBK CAI & 65mm TB. This made a nice increase in throttle response and deeper sound. After reading this article I’m wondering what, if anything to do about running straight pipes? Should we install a crossover mid pipe? Would a custom tune help? Any advice would be great.

  • http://www.mustangcars.info Mustang Blog

    Great article 😀

  • Alcazarjorge

    Hey I’ve got a 01 mustang gt with a BBk Cold Air Intake and Flowmaster 40″s on the stock H-pipe, but im thinking of doing some muffler deletes in place of the flowmasters, what would change and would the computer throw a code

  • JOhnnn

    If your exhaust headers and o2 sensor are hitting your trans pan is that really bad? And how much does it cost to fix a left front frame rail crack?

  • http://www.facebook.com/josh.dyer.756 Josh Dyer

    I have a 95′ mustang gt with a 331 stroker moded ( 302 (5.0) Block ) and a tci street fighter c4 auto trans with a shift kit, I am trying to find a set of full length headers for this aplication, but everything I look at is for a manual trans, does anyone know where I can find a set of full length headers?