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BBK Catted X-Pipe (99-04 4.6L)

Market Price $482.99 You Save 13% ($63.00)
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  • Item 56134
  • MPN# 1670

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Features & Details

  • Improves Exhaust Flow and Sound
  • Raspy Race Car Growl
  • High Flow Catalytic Converters Included
  • 2-1/2" Mandrel-Bent Aluminized Tubing
  • Fits 1999-2004 GT, Bullitt, Mach 1, and SVT Cobra
Increases Overall Performance. Add even more horsepower and torque to the rear wheels of your 4.6L Mustang with a BBK Catted X pipe. A BBK catted X pipe will greatly improve your pony's exhaust flow to increase overall performance and sound.

Race Car Growl. This free flowing BBK x-pipe not only increases power, but it also adds a crisp raspy, race car growl to the sound of your exhaust with its modern "X" crossover pipe design.

Durable Construction. BBK's X-pipes use a free-flowing 2-1/2" diameter CNC mandrel bent aluminized tubing and a merged X crossover to improve flow. And features High flow catalytic converters to provide a significant horsepower increase over the restrictive stock cats.

Application. Specifically designed to fit the 1999 to 2004 4.6L Mustangs, including the GT, Bullitt, Mach 1 and SVT Cobra. This Catted X-pipe is a direct fit replacement for the stock mid pipe.

Technical Note. This BBK product is not legal for use in emission restrictive states.

Fitment: 1999 2000 2001 2002 2003 2004 Details

What's in the Box
  • (1) Catted X-pipe
  • (2) Down pipes
  • (4) Bolts
  • (8) Flat washers
  • (4) Washers
  • (4) Nuts
  • (2) Hose clamps
Installation Info
Tech Specs
Mid Pipe Specifications
Style Mid Pipe: Standard length "X" Type Headers Required: Shorty or Stock Manifolds
Piping Material: Aluminized Steel Piping Size: 2.5"
Catalytic Converter: Yes Fitment: 1999-2004 GT, Bullitt,
Mach 1, Cobra
Will it fit my Mustang?
  • Bullitt - 01
  • Mach 1 - 03, 04
  • Cobra - 99, 01, 03, 04
  • GT - 99, 00, 01, 02, 03, 04

People Who Bought This Item Also Bought

Most Helpful Reviews

Does What it Needs to and More

First off, BBK makes some great products all through the intake and exhaust train, and this X pipe is no exception. Anyone with an axle-back exhaust (Flowmaster American Thunder, Pypes, Magnaflow etc.) ...

Read More
Helpful (6)

Good product. Better then expected

I received the x -pipe and the box was beat up checked everything over and it seemed to be in good shape. The installation instructions were absolutely worthless. "Take off your old one install the bbk ...

Read More
Helpful (3)

Overall Rating 4.4 out of 5 stars
Read All 21 Reviews

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7 Questions / 5 Answers

Ask a Question

I have a 2003 cobra. Will this system mate up with the JBA shorty headers sold on AM?


  • This mid-pipe will work with any shorty headers yes!


Helpful (0)

Will this x pipe work with Borla ATAK cat-back exhaust, and BBK ceramic tuned shorty headers?


  • This mid-pipe will work with the BBK ceramic shorty headers as those headers are designed to mate up to this mid-pipe.


Helpful (0)

Will these fit with BBK performance headers, and Borla ATAK cat-back exhaust?


i currently have an slp cat back exhaust on my 01 GT will these fit it and if i later down the road want to get long tube headers will these no longer by any good?


  • This X-pipe will work together with your SLP cat-back exhaust as long as the exhaust pipe size is 2.5" in diameter. As far as potentially changing your setup to include long tube headers, you will need a matching mid-pipe to go with whichever brand long tube headers you choose for best fitment.


Helpful (0)

I'm debating from an offload or the catted bbl x for my slp lm1 but I'm worried if i buy the catted x it will make my car quite when I'm trying to make it louder but not obnoxious so my question is will this x type make my car sound louder and better or em i better of getting a offroad x


  • I have this xpipe on my 04 gt with a custom fabricated catback. it definitely gives the car a somewhat unique tone and makes it louder. on colder days i even get a few crackles and pops as im driving. with the off road x pipe you'd more than likely get a louder sound and more of the crackling as it doesnt have the restriction from the cats, however it might be overly loud.


Helpful (0)

would this fit a v6 with an american thunder series catback?


  • This BBK X-pipe will not bolt up properly to a V6. To convert to dual exhaust, you would need a mid-pipe designed for the V6 and compatible with a GT catback. If you have any additional questions, do give us a call - we'd be happy to help!


Helpful (0)

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Customer Reviews (21) Write a Review

Overall Rating 4.4

out of 5 stars

Installation Time:Full Day

Installation Cost:$100-$250

  • Loudness / Volume 4.277778 4.3
  • Exhaust Note 4.5 4.5
  • Fit & Finish 4.5 4.5
  • Bang For Your Buck 4.277778 4.3

  • 5/5

    May 28, 2011

    Does What it Needs to and More

    First off, BBK makes some great products all through the intake and exhaust train, and this X pipe is no exception. Anyone with an axle-back exhaust (Flowmaster American Thunder, Pypes, Magnaflow etc.) that bought the axle back to bolt up to their stock H pipe has a lot to gain from this X pipe setup. It is quality built, and its' 'X' flow pattern looks a lot smoother than others, to boot. The installation went well, and would have been much quicker for me if I didn't break off one of the bolt studs on my factory headers. After we solved that hiccup everything went great. Only thing - the O2 sensors are slightly offset from the stock H pipe. I had to take off the plastic wiring harness mounts from the frame they were stuck in on three of the four O2 sensors to let the stock wiring reach. Even so, there was just enough room that the wires are in no danger of frying themselves on the exhaust piping, though you'll want to have some electric tape handy so you can secure the left and right sensor wires (after the cats) to each other. As I said before, if you have an axle-back system and haven't upgraded your midpipe - the difference I noticed after install on my Flowmaster system was /substantial/. Fitment was almost perfect, which is great considering I have an aftermarket axle-back. The BBK X pipe design is simple but wonderfully effective, and even the first few minutes in the parking lot were a joy to hear and feel the car breathe so much better - they aren't BSing when they say 30-40% more throughput with this X pipe than the stock H pipe. The only hang-up I have is that my exhaust definitely sits a little lower than it did, but I'll likely invest in some after-market hangars and cinch it up. Overall exceptional quality, great sound, and a very satisfied customer.


    Year: 2001 Submodel: GT

    Helpful (6)

  • 4/5

    Installation Time: Afternoon

    October 15, 2012

    Good product. Better then expected

    I received the x -pipe and the box was beat up checked everything over and it seemed to be in good shape. The installation instructions were absolutely worthless. "Take off your old one install the bbk x pipe in reverse" Seriously!! Anyway after the install which is not to terrible. The pipes mounted up very nicely with no problems. The O2 holes are a little low on the front pipes and it makes it hard to attach the the O2 sensors. The sound is not noticeably louder but it does have a very tinny sound next to walls at 2k on my Mach 1. All other RPMS were fine. Fit very well lighter then stock and looks much cleaner under the car as well.


    Year: 2003 Submodel: Mach 1 St Louis, MO, USA

    Helpful (3)

  • 4/5

    May 31, 2011

    Bolt On doesn't always mean Direct Replacement

    I just installed this on an 04 Cobra that has flowmaster's original 40 series mufflers. PROS: sounds great with a nice growl to it, the clamps it comes with sealed great with no leaks, sits nice and high off the ground CONS: ball joints that connect from xpipe to cat back were way too open leaving gaps needed to close them up with a hammer, doesn't line up with with catback but a little bit of muscle and a friend went a long way, didn't come with the insert that goes inside the driver side pipe between the header and the pipe but I was able to reuse the one from the MRT hpipe i had on before. OVERALL: except for the metal fabrication work and "persuasion" it took to get everything to line up im satisfied with this product. it looks and sounds great, and i can't wait for it to break in nicely to really open up its lungs.


    Year: 2004 Submodel: Cobra

    Helpful (3)

  • 5/5

    Installation Time: Afternoon

    September 15, 2013

    Excellent !!!

    Bought this X pipe to go along with the BBK ceramic shorty headers and Flowmaster exhaust and I couldn't ask for a better fit or sound that this set up provides. Install was easy and takes very little time for this part. I would recommend this product for any mustang owner who uses their vehicle for daily driving and still wants that agressive sound and feel.


    Year: 2002 Submodel: GT Edgewood, MD, USA

    Helpful (2)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: 0-$100

    April 18, 2013

    Catted BBK X Pipe

    The BBK x pipe does exactly what it says it does. It didnt make my exhaust much louder, if any, but it made the exhaust note amazing with my Magnapacks! It made the exhaust note much deeper, and it isnt raspy at all. After the install, I could really hear and feel the engine breathing better. It also seemed to have made my K&N ram air intake louder. I am very pleased with my purchase.


    Year: 2002 Submodel: GT Denton

    Helpful (2)

  • 5/5

    Installation Time: Afternoon

    October 21, 2012

    BBK X-Pipe

    The X-Pipe was very easy to install. It took about three hours to install. I have loudmouth CAT-BAK and BBK cold-air intake and BBK throttle body. I also thave my Mustang on the performance setting on my BAMA Tuner. The BBK X-Pipe rally made my car rumble and sound great. I am so happy I wen twith the BBK X-pipe. I was looking at the Pypes and BBK X-pipe and there were to many reviews with problems installing the Pypes X-pipe. The BBK X-Pipe fit very well and did not have to cut or make any type of modifications. Great product


    Year: 2004 Submodel: GT WV

    Helpful (2)

  • 4/5

    Installation Time: Afternoon

    April 27, 2012

    Loud but not obnoxious

    I have been running with BBK shorty headers, BBK O/R X, and SLP LM1 cat back exhaust. Let me just say that I love the look, feel, & sound of Mustangs yet I am not a street/track racer. With that in mind I have to say with the way I had my exhaust it was obnoxiously LOUD and you definitely can smell your exhaust fumes on you after you get out. I keep my Mustang in the garage and I leave for work really early…let’s just say that when I start my Mustang it sounds as if a bomb just went off and fills the house with exhaust fumes. While I like loud Mustangs, driving with the windows up for an extended period of time tends to get a little annoying. If you like hearing the sound of a boat for extended period of times then an O/R X will be to your liking. I am fully aware that I am giving up HP by switching back to a catted X but I felt the O/R X was at times overly obnoxious. I also am pleased to no longer smell like fumes when leaving my Mustang. If you’re going to run SLP’s which are known for being really loud on their own, I would recommend going with a catted X vs the O/R X. If you’re mostly concerned with getting the most HP/loudness no worries over fumes then the O/R X will suit you better. After experiencing both types of X pipes, the catted X suits my lifestyle and I couldn’t be happier with the end results.


    Year: 2000 Submodel: GT

    Helpful (2)

  • 4/5

    Installation Time: Shop Install

    November 21, 2011

    Everything that is promised (Product & Service), and more...

    BBK cold air, AccuFab TB/Plenum combo, BBK catted x-pipe, shorty ceramic coated headers & Am Thunder exhaust completely changed the performance of my '03 GT. Incr. range of RPM thru all gears, old school, deep rumble. 3-5 mpg gain, SuperFlow Dyno confirms claimed HP/Trq gains. x-pipe had to be replaced, however, AM cust service (Mike, Rob & Karen) was spot on and went over & above to insure I was completely satisfied....


    Year: 2003 Submodel: GT Leesburg, GA

    Helpful (2)

  • 5/5

    July 13, 2016

    Very Happy With Noise and Fitment

    I ordered the catted X-pipe because Illinois emission laws require them and even with the cats I must say there is a definite improvement in sound quality along with a slight increase in horsepower. My car sounds much raspier and more aggressive than it used to. I ran with the stock H-pipe on my '02 GT for about a year and hated the sound of it. The only hard part you might run into is fitting the down pipes on because it is such a tight space to work in. Just be cautious about scraping (especially if your Mustang is lowered) since the X-pipe sits slightly lower than the standard H-pipe does.


    Year: 2002 Submodel: GT

    Helpful (1)

  • 5/5

    Installation Time: Afternoon

    May 27, 2016

    for be legal in my city

    easy for install i made myself on my draway . and very fast for livraison at my house


    Year: 2003 Submodel: GT

    Helpful (1)

  • 3/5

    Installation Time: Less than 1 Hour

    April 17, 2014

    Catted X-pipe

    If you do not want your car too loud this product is good but my check engine light came on within the first 700 miles and said the catalytic threshold was too low. If I had know that my check engine light was going to come on I would not have wasted 200$ on the catted x pipe.


    Year: 2003 Submodel: Mach 1 Marysville, WA, USA

    Helpful (1)

    • Response from AmericanMuscle

      There are a few things that could be causing that CEL aside from the midpipe itself. Give our customer service a call if you'd like any suggestions. If it turns out that there is something wrong with the midpipe, BBK does have a 1-year warranty on their products. We'll do whatever we can to help get this resolved.

      Lisa , Customer Care

  • 4/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    April 05, 2014


    2 reasons for the review. 1 the price compared to performance and second after reading the reviews nobody mentioned the on an 04 GT mustang I would have to but new o2 sensors because the old ones would not reach. It cost me an extra $150 bucks. It does run smoother and picks up speed a bit more not so much that roarrrrr I was looking for.


    Year: 2004 Submodel: GT Baton Rouge, LA, USA

    Helpful (1)

  • 4/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    March 27, 2014

    Great X-pipe

    After having the x-pipe installed, I had noticed the better sounding of my exhaust system. This is a great add on to my mustang including the pypes mufflers. The only thing is that the cats hang a little low and after driving at highway speeds do not park on high grass or you may notice the grass starting to smoke.


    Year: 2000 Submodel: GT Jacksonville, FL, USA

    Helpful (1)

  • 5/5

    Installation Time: Less than 1 Hour

    March 02, 2014

    Nice fitment. Nice hardware included in kit.

    I recently installed this x-pipe kit and couldn't be happier. This kit keeps me legal and also keeps my car from having the raspy sound that is notorious with 4v mod motor cars. Hardware included is very nice and installation was a breeze.


    Year: 2003 Submodel: Mach 1 Hermitage, Nashville, TN 37076, USA

    Helpful (1)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    January 19, 2014

    2000 Mustang GT BBK catted x-pipe and borla stingers

    Always wanted the O/R X, but didn't want to deal with emissions. Got the catted X and it still sounds amazing. Kept the stock headers, and everything fits perfectly. It gave my GT the sound I've been wanting since I was 16. The throaty rumble is turning heads.


    Year: 2000 Submodel: GT Franklin, TN, USA

    Helpful (1)

  • 1/5

    Installation Time: Shop Install

    Installation Cost: $250-$500

    August 01, 2012

    Cats both broke in 3-4 months

    I initially was fairly pleased with the catted X-pipes but I just had to get a second set sent out because I developed a knocking noise in the exhaust. I took the car back to the shop who informed me that both Cats were broken. I don't know if they were dropped or damaged in shipping which lead to early deterioration but AM did honor the warranty and is sending out new set ASAP. The second time aroundI considered getting off road X-pipes to avoid further cat issues but after reading reviews it sounded like off road pipes would be super loud and produced a bad smell. Therefore, I'm giving the BBK catted X-pipes a second chance thinking that they were damaged in shipping; my BBK header box had been thrown around and had a hole in it by the time that it got to me but the X-pipes box looked just fine from the exterior. My only comment on the pipes other than they sounded great along with my Flowmasters is that the shop had to modify them slightly to get them to work with BBK shorty headers. The shop welded the two together because they wanted to have a good union between the two not liking the bracket if I remember correctly.


    Year: 1999 Submodel: GT

    Helpful (1)

  • 5/5

    Installation Time: Weekend

    April 27, 2012

    BBK Catted X-Pipe

    Great stock replacement, fits directly and perfectly where old on was like it said. It does hang a little lower than the stock, I have to be careful going over speed bumps and what not, but overall great x-pipe and sounds awesome with my SLOW Loudmouth II cutback exhaust and fits perfectly with that as well.


    Year: 2003 Submodel: GT Phoenix, AZ, USA

    Helpful (1)

  • 5/5

    Installation Time: Less than 1 Hour

    November 23, 2011

    Great sound! Awesome quality! Decent HP gains!

    Fast Shipping, quality product, Excellent sound, and decent HP gains (12 HP at the Dyno). Thanks AM. Lorne


    Year: 2003 Submodel: GT Portland, OR

    Helpful (1)

  • 5/5

    Installation Time: Afternoon

    November 16, 2011

    Nice Xpipe hangs a bit low

    One of the cool things about American Muscle is the customer reviews. Which are very helpful in not only determining what to purchase but also customer experience's installing product's. I like to take an overview before installing any new part on my Mustang. For this installation I knew replacing the mid pipe was not going to be difficult given the fact the exhaust manifolds as well as the Cat backs had recently been replaced. I sprayed PB blaster on all four o2 sensors the night before installation. 3 came off easily one stripped out leaving me to buy a new Pretty straight forward install I did mark the two pipes with a Magic marker that are join by the couplings provided so that the pipes would be as tight as possible. After installation I drove the car for about a week put it back on the lift and found the bolts from the mid pipe to exhaust manifolds where a bit loose on both sides . I guess the only advice I could give is to make sure to re torque the bolts after about a week or so of driving I also applied thread lock red on all bolts ,With any luck you may not have to.


    Year: 2004 Submodel: Bullitt Cape cod

    Helpful (1)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    July 21, 2017

    Genesee Valley Ford is number one in my book.

    Great item. Fit and finish is excellent. I would recommend this product.


    Year: 2001 Submodel: Cobra

    Helpful (0)

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